A comparative Study of Aptasensor Vs Immunosensor for Label-Free PSA Cancer Detection on GQDs-AuNRs Modified Screen-Printed Electrodes.

PubMed

Srivastava, Monika; Nirala, Narsingh R; Srivastava, S K; Prakash, Rajiv

2018-01-31

Label-free and sensitive detection of PSA (Prostate Specific Antigen) is still a big challenge in the arena of prostate cancer diagnosis in males. We present a comparative study for label-free PSA aptasensor and PSA immunosensor for the PSA-specific monoclonal antibody, based on graphene quantum dots-gold nanorods (GQDs-AuNRs) modified screen-printed electrodes. GQDs-AuNRs composite has been synthesized and used as an electro-active material, which shows fast electron transfer and catalytic property. Aptamer or anti-PSA has immobilized onto the surface of modified screen printed electrodes. Three techniques are used simultaneously, viz. cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedence spectroscopy (EIS) to investigate the analytical performance of both PSA aptasensor and PSA immunosensor with its corresponding PSA antigen. Under optimum conditions, both sensors show comparable results with an almost same limit of detection (LOD) of 0.14 ng mL -1 . The results developed with aptasensor and anti-PSA is also checked through the detection of PSA in real samples with acceptable results. Our study suggests some advantages of aptasensor in terms of better stability, simplicity and cost effectiveness. Further our present work shows enormous potential of our developed sensors for real application using voltammetric and EIS techniques simultaneous to get reliable detection of the disease.

Screen-Printed Carbon Electrodes Modified with Cobalt Phthalocyanine for Selective Sulfur Detection in Cosmetic Products

PubMed Central

Chen, Pei-Yen; Luo, Chin-Hsiang; Chen, Mei-Chin; Tsai, Feng-Jie; Chang, Nai-Fang; Shih, Ying

2011-01-01

Cobalt phthalocyanine (CoPc) films were deposited on the surface of a screen-printed carbon electrode using a simple drop coating method. The cyclic voltammogram of the resulting CoPc modified screen-printed electrode (CoPc/SPE) prepared under optimum conditions shows a well-behaved redox couple due to the (CoI/CoII) system. The CoPc/SPE surface demonstrates excellent electrochemical activity towards the oxidation of sulfur in a 0.01 mol·L−1 NaOH. A linear calibration curve with the detection limit (DL, S/N = 3) of 0.325 mg·L−1 was achieved by CoPc/SPE coupled with flow injection analysis of the sulfur concentration ranging from 4 to 1120 mg·L−1. The precision of the system response was evaluated (3.60% and 3.52% RSD for 12 repeated injections), in the range of 64 and 480 mg·L−1 sulfur. The applicability of the method was successfully demonstrated in a real sample analysis of sulfur in anti-acne creams, and good recovery was obtained. The CoPc/SPE displayed several advantages in sulfur determination including easy fabrication, high stability, and low cost. PMID:21747708

Screen-printed electrode modified with carbon black and chitosan: a novel platform for acetylcholinesterase biosensor development.

PubMed

Talarico, Daria; Arduini, Fabiana; Amine, Aziz; Cacciotti, Ilaria; Moscone, Danila; Palleschi, Giuseppe

2016-10-01

We report a screen-printed electrode (SPE) modified with a dispersion of carbon black (CB) and chitosan by drop casting. A cyclic voltammetry technique towards ferricyanide, caffeic acid, hydroquinone, and thiocholine was performed and an improvement of the electrochemical response with respect to bare SPE as well as SPE modified only with chitosan was observed. The possibility to detect thiocholine at a low applied potential with high sensitivity was exploited and an acetylcholinesterase (AChE) biosensor was developed. A dispersion of CB, chitosan, and AChE was used to fabricate this biosensor in one step by drop casting. The enzymatic activity of the immobilized AChE was determined measuring the enzymatic product thiocholine at +300 mV. Owing to the capability of organophosphorus pesticides to inhibit AChE, this biosensor was used to detect these pollutants, and paraoxon was taken as model compound. The enzyme inhibition was linearly related to the concentration of paraoxon up to 0.5 μg L(-1), and a low detection limit equal to 0.05 μg L(-1) (calculated as 10% of inhibition) was achieved. This biosensor was challenged for paraoxon detection in drinking waters with satisfactory recovery values. The use of AChE embedded in a dispersion of CB and chitosan allowed an easy and fast production of a sensitive biosensor suitable for paraoxon detection in drinking waters at legal limit levels. Graphical Abstract Biosensors based on screen-printed electrodes modified with Acetylcholinesterase, Carbon Black, and Chitosan for organophosphorus pesticide detection.

Development of electrochemical sensor for the determination of palladium ions (Pd2+) using flexible screen printed un-modified carbon electrode.

PubMed

Velmurugan, Murugan; Thirumalraj, Balamurugan; Chen, Shen-Ming; Al-Hemaid, Fahad M A; Ajmal Ali, M; Elshikh, Mohamed S

2017-01-01

To date, the development of different modified electrodes have received much attention in electrochemistry. The modified electrodes have some drawbacks such as high cost, difficult to handle and not eco friendly. Hence, we report an electrochemical sensor for the determination of palladium ions (Pd 2+ ) using an un-modified screen printed carbon electrode has been developed for the first time, which are characterized and studied via scanning electron microscope and cyclic voltammetry. Prior to determination of Pd 2+ ions, the operational conditions of un-modified SPCE was optimized using cyclic voltammetry and showed excellent electro-analytical behavior towards the determination of Pd 2+ ions. Electrochemical determination of Pd 2+ ions reveal that the un-modified electrode showed lower detection limit of 1.32μM with a linear ranging from 3 to 133.35μM towards the Pd 2+ ions concentration via differential pulse voltammetry. The developed sensor also applied to the successfully determination of trace level Pd 2+ ions in spiked water samples. In addition, the advantage of this type of electrode is simple, disposable and cost effective in electrochemical sensors. Copyright © 2016 Elsevier Inc. All rights reserved.

A screen-printed carbon electrode modified with gold nanoparticles, poly(3,4-ethylenedioxythiophene), poly(styrene sulfonate) and a molecular imprint for voltammetric determination of nitrofurantoin.

PubMed

Dechtrirat, Decha; Yingyuad, Peerada; Prajongtat, Pongthep; Chuenchom, Laemthong; Sriprachuabwong, Chakrit; Tuantranont, Adisorn; Tang, I-Ming

2018-04-23

A molecularly imprinted polymer (MIP) and a nanocomposite prepared from gold nanoparticles (AuNP) and poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) were deposited on a screen-printed carbon electrode (SPCE). The nanocomposite was prepared by one-pot simultaneous in-situ formation of AuNPs and PEDOT:PSS and was then inkjet-coated onto the SPCE. The MIP film was subsequently placed on the modified SPCE by co-electrodeposition of o-phenylenediamine and resorcinol in the presence of the antibiotic nitrofurantoin (NFT). Using differential pulse voltammetry (DPV), response at the potential of ~ 0.1 V (vs. Ag/AgCl) is linear in 1 nM to 1000 nM NFT concentration range, with a remarkably low detection limit (at S/N = 3) of 0.1 nM. This is two orders of magnitude lower than that of the control MIP sensor without the nanocomposite interlayer, thus showing the beneficial effect of AuNP-PEDOT:PSS. The electrode is highly reproducible (relative standard deviation 3.1% for n = 6) and selective over structurally related molecules. It can be re-used for at least ten times and was found to be stable for at least 45 days. It was successfully applied to the determination of NFT in (spiked) feed matrices and gave good recoveries. Graphical abstract Schematic representation of a voltammetric sensor for the determination of nitrofurantoin. The sensor is based on a screen-printed carbon electrode (SPCE) modified with an inkjet-printed gold nanoparticles-poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) nanocomposite and a molecularly imprinted polymer.

Highly selective dopamine electrochemical sensor based on electrochemically pretreated graphite and nafion composite modified screen printed carbon electrode.

PubMed

Ku, Shuhao; Palanisamy, Selvakumar; Chen, Shen-Ming

2013-12-01

Herein, we report a highly selective dopamine electrochemical sensor based on electrochemically pretreated graphite/nafion composite modified screen printed carbon (SPC) electrode. Electrochemically activated graphite/nafion composite was prepared by using a simple electrochemical method. Scanning electron microscope (SEM) used to characterize the surface morphology of the fabricated composite electrode. The SEM result clearly indicates that the graphitic basal planes were totally disturbed and leads to the formation of graphite nanosheets. The composite modified electrode showed an enhanced electrocatalytic activity toward the oxidation of DA when compared with either electrochemical pretreated graphite or nafion SPC electrodes. The fabricated composite electrode exhibits a good electrocatalytic oxidation toward DA in the linear response range from 0.5 to 70 μM with the detection limit of 0.023 μM. The proposed sensor also exhibits very good selectivity and stability, with the appreciable sensitivity. In addition, the proposed sensor showed satisfactory recovery results toward the commercial pharmaceutical DA samples. Copyright © 2013 Elsevier Inc. All rights reserved.

[Investigation on simultaneous determination of dihydroxybenzene isomers in water samples using multi-walled carbon nanotube modified screen-printed electrode].

PubMed

Li, Yuan-Ting; Li, Da-Wei; Song, Wei; Long, Yi-Tao

2011-02-01

A disposable electrode, multi-walled carbon nanotube modified screen printed electrode (MWCNT/SPE), had been fabricated using screen printing technology and drop-coating method to determine dihydroxybenzene isomers (hydroquinone, catechol and resorcinol). The cyclic voltammetry behavior of dihydroxybenzene isomers had been investigated with the MWCNT/SPE. The results reveal that MWCNT/SPE, which shows a strong electrocatalytic activity for the oxidation of dihydroxybenzenes, can entirely separate the oxidation peaks of them. According to differential pulse voltammetry tests, the peak currents of dihydroxybenzene isomers are linear to their concentrations at the range of 8.20 x 10(-6) -1.00 x 10(-3), 8.20 x 10(-6) -1.00 x 10(-3) and 1.64 x 10(-5) -1.16 x 10(-3) mol x L(-1), with the detection limits of 4.34 x 10(-6), 3.42 x 10(-6) and 6.70 x 10(-6) mol x L(-1) for hydroquinone, catechol and resorcinol, respectively. For the determination of dihydroxybenzene isomers in water samples, the value of recovery found by standard addition method was in the range of 96.2%-104.9%. These results indicate MWCNT/SPE can be applied to rapid in-situ determination of dihydroxybenzenes-polluted water samples.

Voltammetric determination of the Escherichia coli DNA using a screen-printed carbon electrode modified with polyaniline and gold nanoparticles.

PubMed

Shoaie, Nahid; Forouzandeh, Mehdi; Omidfar, Kobra

2018-03-12

The authors describe an electrochemical assay for fast detection of Escherichia coli (E. coli). It is based on a dual signal amplification strategy and the use of a screen-printed carbon electrode (SPCE) whose surface was modified with a polyaniline (PANI) film and gold nanoparticles (AuNPs) via cyclic voltammetry (CV). In the next step, avidin was covalently immobilized on the PANI/AuNP composite on the SPCE surface. Subsequently, the biotinylated DNA capture probe was immobilized onto the PANI/AuNP/avidin-modified SPCE by biotin-avidin interaction. Then, DNA of E.coli, digoxigenin-labeled DNA detector probe and anti-digoxigenin-labeled horseradish peroxidase (HRP) were placed on the electrode. 3,3',5,5'-Tetramethylbenzidine (TMB) and H 2 O 2 solution were added and the CV electrochemical signal was generated at a potential of -0.1 V (vs. Ag/AgCl) and a scan rate 50 mV.s -1 . The assay can detect 4 × 10 6 to 4 CFU of E. coli without DNA amplification. The biosensor is highly specific over other pathogens including Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis, Staphylococcus haemolyticus and Pseudomonas aeruginosa. It can be concluded that this genosensor has an excellent potential for rapid and accurate diagnosis of E.coli inflicted infections. Graphical Abstract Schematic of an electrochemical E. coli genosensor based on sandwich assay on a polyaniline/gold nanoparticle-modified screen printed carbon electrode (SPCE). The biosensor can detect 4 × 10 6 to 4 CFU of E. coli without DNA amplification.

Determination of total and electrolabile copper in agricultural soil by using disposable modified-carbon screen-printed electrodes.

PubMed

Faucher, Stéphane; Cugnet, Cyril; Authier, Laurent; Lespes, Gaëtane

2014-02-01

The objective of the study is to evaluate modified-carbon screen-printed working electrodes (SPE) combined with square wave anodic stripping voltammetry (SWASV) to determine electrolabile and total copper in soils with the perspective to assess the environmental hazard resulting from copper anthropogenic contamination. The voltammetric method was investigated using a mineralized certified reference soil such that it can be assumed that the copper was totally under electrolabile form in the solution of mineralized soil. In optimal conditions, a copper recovery of 97% and a relative standard deviation (RSD) of 9% were found. The limits of detection and quantification for copper were 0.4 and 1.3 μg L(-1), respectively. Finally, the method was applied on soil leachates, which allowed evaluating the cupric transfer from the soil to the leachates and quantifying the electrolabile copper part in leachates.

Methyl parathion detection in vegetables and fruits using silver@graphene nanoribbons nanocomposite modified screen printed electrode

NASA Astrophysics Data System (ADS)

Govindasamy, Mani; Mani, Veerappan; Chen, Shen-Ming; Chen, Tse-Wei; Sundramoorthy, Ashok Kumar

2017-04-01

We have developed a sensitive electrochemical sensor for Organophosphorus pesticide methyl parathion (MP) using silver particles supported graphene nanoribbons (Ag@GNRs). The Ag@GNRs nanocomposite was prepared through facile wet chemical strategy and characterized by TEM, EDX, XRD, Raman, UV-visible, electrochemical and impedance spectroscopies. The Ag@GNRs film modified screen printed carbon electrode (SPCE) delivers excellent electrocatalytic ability to the reduction of MP. The Ag@GNRs/SPCE detects sub-nanomolar concentrations of MP with excellent selectivity. The synergic effects between special electrocatalytic ability of Ag and excellent physicochemical properties of GNRs (large surface area, high conductivity, high area-normalized edge-plane structures and abundant catalytic sites) make the composite highly suitable for MP sensing. Most importantly, the method is successfully demonstrated in vegetables and fruits which revealed its potential real-time applicability in food analysis.

Chip-based generation of carbon nanodots via electrochemical oxidation of screen printed carbon electrodes and the applications for efficient cell imaging and electrochemiluminescence enhancement

NASA Astrophysics Data System (ADS)

Xu, Yuanhong; Liu, Jingquan; Zhang, Jizhen; Zong, Xidan; Jia, Xiaofang; Li, Dan; Wang, Erkang

2015-05-01

A portable lab-on-a-chip methodology to generate ionic liquid-functionalized carbon nanodots (CNDs) was developed via electrochemical oxidation of screen printed carbon electrodes. The CNDs can be successfully applied for efficient cell imaging and solid-state electrochemiluminescence sensor fabrication on the paper-based chips.A portable lab-on-a-chip methodology to generate ionic liquid-functionalized carbon nanodots (CNDs) was developed via electrochemical oxidation of screen printed carbon electrodes. The CNDs can be successfully applied for efficient cell imaging and solid-state electrochemiluminescence sensor fabrication on the paper-based chips. Electronic supplementary information (ESI) available: Experimental section; Fig. S1. XPS spectra of the as-prepared CNDs after being dialyzed for 72 hours; Fig. S2. LSCM images showing time-dependent fluorescence signals of HeLa cells treated by the as-prepared CNDs; Tripropylamine analysis using the Nafion/CNDs modified ECL sensor. See DOI: 10.1039/c5nr01765c

Thin-layer voltammetry of soluble species on screen-printed electrodes: proof of concept.

PubMed

Botasini, S; Martí, A C; Méndez, E

2016-10-17

Thin-layer diffusion conditions were accomplished on screen-printed electrodes by placing a controlled-weight onto the cast solution and allowing for its natural spreading. The restricted diffusive conditions were assessed by cyclic voltammetry at low voltage scan rates and electrochemical impedance spectroscopy. The relationship between the weight exerted over the drop and the thin-layer thickness achieved was determined, in such a way that the simple experimental set-up designed for this work could be developed into a commercial device with variable control of the thin-layer conditions. The experimental results obtained resemble those reported for the voltammetric features of electroactive soluble species employing electrodes modified with carbon nanotubes or graphene layers, suggesting that the attainment of the benefits reported for these nanomaterials could be done simply by forcing the solution to spread over the screen-printed electrodic system to form a thin layer solution. The advantages of thin-layer voltammetry in the kinetic characterization of quasi-reversible and irreversible processes are highlighted.

Bulk-modified modified screen-printing carbon electrodes with both lactate oxidase (LOD) and horseradish peroxide (HRP) for the determination of L-lactate in flow injection analysis mode.

PubMed

Ghamouss, Fouad; Ledru, Sophie; Ruillé, Nadine; Lantier, Françoise; Boujtita, Mohammed

2006-06-16

A screen-printed carbon electrode modified with both HRP and LOD (SPCE-HRP/LOD) has been developed for the determination of L-lactate concentration in real samples. The resulting SPCE-HRP/LOD was prepared in a one-step procedure, and was then optimised as an amperometric biosensor operating at [0, -100]mV versus Ag/AgCl for L-lactate determination in flow injection mode. A significant improvement in the reproducibility (coefficient variation of about 10%) of the preparation of the biosensors was obtained when graphite powder was modified with LOD in the presence of HRP previously oxidised by periodate ion (IO4-). Optimisation studies were performed by examining the effects of LOD loading, periodation step and rate of the binder on analytical performances of SPCE-HRP/LOD. The sensitivity of the optimised SPCE-HRP/LOD to L-lactate was 0.84 nAL micromol(-1) in a detection range between 10 and 180 microMol. The possibility of using the developed biosensor to determine L-lactate concentrations in various dairy products was also evaluated.

Rapid detection of ssDNA and RNA using multi-walled carbon nanotubes modified screen-printed carbon electrode.

PubMed

Ye, Yongkang; Ju, Huangxian

2005-11-15

A method for rapid sensitive detection of DNA or RNA was designed using a composite screen-printed carbon electrode modified with multi-walled carbon nanotubes (MWNTs). MWNTs showed catalytic characteristics for the direct electrochemical oxidation of guanine or adenine residues of signal strand DNA (ssDNA) and adenine residues of RNA, leading to indicator-free detection of ssDNA and RNA concentrations. With an accumulation time of 5 min, the proposed method could be used for detection of calf thymus ssDNA ranging from 17.0 to 345 microg ml(-1) with a detection limit of 2.0 microg ml(-1) at 3 sigma and yeast tRNA ranging from 8.2 microg ml(-1) to 4.1 mg ml(-1). AC impedance was employed to characterize the surface of modified electrodes. The advantages of convenient fabrication, low-cost detection, short analysis time and combination with nanotechnology for increasing the sensitivity made the subject worthy of special emphasis in the research programs and sources of new commercial products.

A voltammetric method for Fe(iii) in blood serum using a screen-printed electrode modified with a Schiff base ionophore.

PubMed

Mittal, Susheel K; Rana, Sonia; Kaur, Navneet; Banks, Craig E

2018-05-23

Herein, a potent electrochemical ionophore (SMS-2) based on a Schiff base has been used for the modification of a screen-printed electrode (SPE). The modified disposable electrode can selectively detect ferric ions in an aqueous medium. Redox behavior of the proposed strip was characterized using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Incorporation of the ligand in the ink of the SPE enhanced the analytical performance of the electrode, and its surface modification was confirmed by SEM and EDX analysis. Shifting/quenching of the cathodic peak potential of the ionophore after binding with Fe(iii) ions was used to detect and measure the ferric ion concentration. This sensor can identify Fe(iii) in the detection range from 0.625 μM to 7.5 μM. The modified SPE can selectively detect ferric ions in the presence of many other interfering ions and has been successfully used to determine the Fe(iii) content in blood serum samples. The metal-ionophore complex structure was optimized using DFT calculations to study the energetics of the metal-ionophore interactions.

Disposable DNA biosensor with the carbon nanotubes-polyethyleneimine interface at a screen-printed carbon electrode for tests of DNA layer damage by quinazolines.

PubMed

Galandová, Júlia; Ovádeková, Renáta; Ferancová, Adriana; Labuda, Ján

2009-06-01

A screen-printed carbon working electrode within a commercially available screen-printed three-electrode assembly was modified by using a composite of multiwalled carbon nanotubes (MWCNT) dispersed in polyethylenimine (PEI) followed by covering with the calf thymus dsDNA layer. Several electrochemical methods were used to characterize the biosensor and to evaluate damage to the surface-attached DNA: square wave voltammetry of the [Ru(bpy)(3)](2+) redox indicator and mediator of the guanine moiety oxidation, cyclic voltammetry and electrochemical impedance spectroscopy in the presence of the [Fe(CN)(6)](3-/4-) indicator in solution. Due to high electroconductivity and large surface area of MWCNT and positive charge of PEI, the MWCNT-PEI composite is an advantageous platform for the DNA immobilization by the polyelectrolyte complexation and its voltammetric and impedimetric detection. In this respect, the MWCNT-PEI interface exhibited better properties than the MWCNT-chitosan one reported from our laboratory previously. A deep DNA layer damage at incubation of the biosensor in quinazoline solution was found, which depends on the quinazoline concentration and incubation time.

Highly Sensitive Aluminium(III) Ion Sensor Based on a Self-assembled Monolayer on a Gold Nanoparticles Modified Screen-printed Carbon Electrode.

PubMed

See, Wong Pooi; Heng, Lee Yook; Nathan, Sheila

2015-01-01

A new approach for the development of a highly sensitive aluminium(III) ion sensor via the preconcentration of aluminium(III) ion with a self-assembled monolayer on a gold nanoparticles modified screen-printed carbon electrode and current mediation by potassium ferricyanide redox behavior during aluminium(III) ion binding has been attempted. A monolayer of mercaptosuccinic acid served as an effective complexation ligand for the preconcentration of trace aluminium; this led to an enhancement of aluminium(III) ion capture and thus improved the sensitivity of the sensor with a detection limit of down to the ppb level. Under the optimum experimental conditions, the sensor exhibited a wide linear dynamic range from 0.041 to 12.4 μM. The lower detection limit of the developed sensor was 0.037 μM (8.90 ppb) using a 10 min preconcentration time. The sensor showed excellent selectivity towards aluminium(III) ion over other interference ions.

An electrochemical ELISA-like immunosensor for miRNAs detection based on screen-printed gold electrodes modified with reduced graphene oxide and carbon nanotubes.

PubMed

Tran, H V; Piro, B; Reisberg, S; Huy Nguyen, L; Dung Nguyen, T; Duc, H T; Pham, M C

2014-12-15

We design an electrochemical immunosensor for miRNA detection, based on screen-printed gold electrodes modified with reduced graphene oxide and carbon nanotubes. An original immunological approach is followed, using antibodies directed to DNA.RNA hybrids. An electrochemical ELISA-like amplification strategy was set up using a secondary antibody conjugated to horseradish peroxidase (HRP). Hydroquinone is oxidized into benzoquinone by the HRP/H2O2 catalytic system. In turn, benzoquinone is electroreduced into hydroquinone at the electrode. The catalytic reduction current is related to HRP amount immobilized on the surface, which itself is related to miRNA.DNA surface density on the electrode. This architecture, compared to classical optical detection, lowers the detection limit down to 10 fM. Two miRNAs were studied: miR-141 (a prostate biomarker) and miR-29b-1 (a lung cancer biomarker). Copyright © 2014 Elsevier B.V. All rights reserved.

An electrochemical genosensor for Salmonella typhi on gold nanoparticles-mercaptosilane modified screen printed electrode.

PubMed

Das, Ritu; Sharma, Mukesh K; Rao, Vepa K; Bhattacharya, B K; Garg, Iti; Venkatesh, V; Upadhyay, Sanjay

2014-10-20

In this work, we fabricated a system of integrated self-assembled layer of organosilane 3-mercaptopropyltrimethoxy silane (MPTS) on the screen printed electrode (SPE) and electrochemically deposited gold nanoparticle for Salmonella typhi detection employing Vi gene as a molecular marker. Thiolated DNA probe was immobilized on a gold nanoparticle (AuNP) modified SPE for DNA hybridization assay using methylene blue as redox (electroactive) hybridization indicator, and signal was monitored by differential pulse voltammetry (DPV) method. The modified SPE was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and atomic force microscopy (AFM) method. The DNA biosensor showed excellent performances with high sensitivity and good selectivity. The current response was linear with the target sequence concentrations ranging from 1.0 × 10(-11) to 0.5 × 10(-8)M and the detection limit was found to be 50 (± 2.1)pM. The DNA biosensor showed good discrimination ability to the one-base, two-base and three-base mismatched sequences. The fabricated genosensor could also be regenerated easily and reused for three to four times for further hybridization studies. Copyright © 2014 Elsevier B.V. All rights reserved.

A novel Laccase Biosensor based on Laccase immobilized Graphene-Cellulose Microfiber Composite modified Screen-Printed Carbon Electrode for Sensitive Determination of Catechol

PubMed Central

Palanisamy, Selvakumar; Ramaraj, Sayee Kannan; Chen, Shen-Ming; Yang, Thomas C. K.; Yi-Fan, Pan; Chen, Tse-Wei; Velusamy, Vijayalakshmi; Selvam, Sonadevi

2017-01-01

In the present work, we demonstrate the fabrication of laccase biosensor to detect the catechol (CC) using laccase immobilized on graphene-cellulose microfibers (GR-CMF) composite modified screen printed carbon electrode (SPCE). The direct electrochemical behavior of laccase was investigated using laccase immobilized different modified SPCEs, such as GR/SPCE, CMF/SPCE and GR-CMF/SPCE. Compared with laccase immobilized GR and CMF modified SPCEs, a well-defined redox couple of CuI/CuII for laccase was observed at laccase immobilized GR-CMF composite modified SPCE. Cyclic voltammetry results show that the as-prepared biosensor has 7 folds higher catalytic activity with lower oxidation potential towards CC than SPCE modified with GR-CMF composite. Under optimized conditions, amperometric i-t method was used for the quantification of CC, and the amperometric response of the biosensor was linear over the concertation of CC ranging from 0.2 to 209.7 μM. The sensitivity, response time and the detection limit of the biosensor for CC is 0.932 μMμA−1 cm−2, 2 s and 0.085 μM, respectively. The biosensor has high selectivity towards CC in the presence of potentially active biomolecules and phenolic compounds. The biosensor also accessed for the detection of CC in different water samples and shows good practicality with an appropriate repea. PMID:28117357

Evaluating Zeolite-Modified Sensors: towards a faster set of chemical sensors

NASA Astrophysics Data System (ADS)

Berna, A. Z.; Vergara, A.; Trincavelli, M.; Huerta, R.; Afonja, A.; Parkin, I. P.; Binions, R.; Trowell, S.

2011-09-01

The responses of zeolite-modified sensors, prepared by screen printing layers of chromium titanium oxide (CTO), were compared to unmodified tin oxide sensors using amplitude and transient responses. For transient responses we used a family of features, derived from the exponential moving average (EMA), to characterize chemo-resistive responses. All sensors were tested simultaneously against 20 individual volatile compounds from four chemical groups. The responses of the two types of sensors showed some independence. The zeolite-modified CTO sensors discriminated compounds better using either amplitude response or EMA features and CTO-modified sensors also responded three times faster.

PERFORMANCE DEMONSTRATIONS OF ALTERNATIVE SCREEN RECLAMATION PRODUCTS FOR SCREEN PRINTING

EPA Science Inventory

This project evaluated environmentally-preferable products for the screen reclamation process In screen printing during month-long demonstrations at 23 printing facilities nationwide. hrough the Environmental Protection Agency (EPA) Design for the Environment Printing Project, pr...

Method development for the determination of arsenic by sequential injection/anodic stripping voltammetry using long-lasting gold-modified screen-printed carbon electrode.

PubMed

Punrat, Eakkasit; Chuanuwatanakul, Suchada; Kaneta, Takashi; Motomizu, Shoji; Chailapakul, Orawon

2013-11-15

An automated method has been developed for determining the concentration of inorganic arsenic. The technique uses sequential injection/anodic stripping voltammetry with a long-lasting gold-modified screen-printed carbon electrode. The long-lasting gold electrode was electrochemically deposited onto a screen-printed carbon electrode at a potential of -0.5 V vs. Ag/AgCl in a supporting electrolyte solution of 1M hydrochloric acid. Under optimal conditions and the applied potentials, the electrode demonstrated that it can be used for a long time without a renewal process. The linear range for the determination of arsenic(III) was 1-100 μg L(-1), and the limit of detection (LOD) in standard solutions was as low as 0.03 μg L(-1) for a deposition time of 120 s and sample volume of 1 mL. This method was used to determine the concentration of arsenic(III) in water samples with satisfactory results. The LOD in real samples was found to be 0.5 μg L(-1). In addition, speciation between arsenic(III) and arsenic(V) has been achieved with the proposed method using deposition potentials of -0.5 V and -1.5 V for the determination of the arsenic(III) concentration and the total arsenic concentration, respectively; the results were acceptable. The proposed method is an automated system that offers a less expensive alternative for determining trace amounts of inorganic arsenic. © 2013 Elsevier B.V. All rights reserved.

Electrocatalytic oxidation and determination of insulin at nickel oxide nanoparticles-multiwalled carbon nanotube modified screen printed electrode.

PubMed

Rafiee, Banafsheh; Fakhari, Ali Reza

2013-08-15

Nickel oxide nanoparticles modified nafion-multiwalled carbon nanotubes screen printed electrode (NiONPs/Nafion-MWCNTs/SPE) were prepared using pulsed electrodeposition of NiONPs on the MWCNTs/SPE surface. The size, distribution and structure of the NiONPs/Nafion-MWCNTs were characterized by transmission electron microscopy (TEM) and x-ray diffraction (XRD) and also the results show that NiO nanoparticles were homogeneously electrodeposited on the surfaces of MWCNTs. Also, the electrochemical behavior of NiONPs/Nafion-MWCNTs composites in aqueous alkaline solutions of insulin was studied by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy (EIS). It was found that the prepared nanoparticles have excellent electrocatalytic activity towards insulin oxidation due to special properties of NiO nanoparticles. Cyclic voltammetric studies showed that the NiONPs/Nafion-MWCNTs film modified SPE, lowers the overpotentials and improves electrochemical behavior of insulin oxidation, as compared to the bare SPE. Amperometry was also used to evaluate the analytical performance of modified electrode in the quantitation of insulin. Excellent analytical features, including high sensitivity (1.83 μA/μM), low detection limit (6.1 nM) and satisfactory dynamic range (20.0-260.0 nM), were achieved under optimized conditions. Moreover, these sensors show good repeatability and a high stability after a while or successive potential cycling. Copyright © 2013 Elsevier B.V. All rights reserved.

Electroanalytical detection of pindolol: comparison of unmodified and reduced graphene oxide modified screen-printed graphite electrodes.

PubMed

Cumba, Loanda R; Smith, Jamie P; Brownson, Dale A C; Iniesta, Jesús; Metters, Jonathan P; do Carmo, Devaney R; Banks, Craig E

2015-03-07

Recent work has reported the first electroanalytical detection of pindolol using reduced graphene oxide (RGO) modified glassy carbon electrodes [S. Smarzewska and W. Ciesielski, Anal. Methods, 2014, 6, 5038] where it was reported that the use of RGO provided significant improvements in the electroanalytical signal in comparison to a bare (unmodified) glassy carbon electrode. We demonstrate, for the first time, that the electroanalytical quantification of pindolol is actually possible using bare (unmodified) screen-printed graphite electrodes (SPEs). This paper addresses the electroanalytical determination of pindolol utilising RGO modified SPEs. Surprisingly, it is found that bare (unmodified) SPEs provide superior electrochemical signatures over that of RGO modified SPEs. Consequently the electroanalytical sensing of pindolol is explored at bare unmodified SPEs where a linear range between 0.1 μM-10.0 μM is found to be possible whilst offering a limit of detection (3σ) corresponding to 0.097 μM. This provides a convenient yet analytically sensitive method for sensing pindolol. The optimised electroanalytical protocol using the unmodified SPEs, which requires no pre-treatment (electrode polishing) or electrode modification step (such as with the use of RGO), was then further applied to the determination of pindolol in urine samples. This work demonstrates that the use of RGO modified SPEs have no significant benefits when compared to the bare (unmodified) alternative and that the RGO free electrode surface can provide electro-analytically useful performances.

Disposable L-lactate biosensor based on a screen-printed carbon electrode enhanced by graphene

NASA Astrophysics Data System (ADS)

Tu, Dandan; He, Yu; Rong, Yuanzhen; Wang, You; Li, Guang

2016-04-01

In this work, an amperometric L-lactate biosensor based on a graphene-modified screen-printed carbon electrode (SPCE) was constructed. First, the electrocatalytic performance of the SPCE modified with graphene by a one-step electrodeposition process (OerGO/SPCE) was investigated. The cyclic voltammogram of OerGO/SPCE, which showed a well-defined redox peak, had a smaller peak potential separation than that of SPCE, revealing the improvement in electron transfer speed brought about by modifying with graphene. Next, lactate oxidase and potassium ferricyanide were dropped on the OerGO/SPCE to construct a graphene-modified L-lactate biosensor (LOD/K3[Fe(CN)6]/OerGO/SPCE). The proposed biosensor, with a detection limit of 60 μM, had a high sensitivity (42.42 μA mM-1 cm-2) when working at a low working potential (0.15 V). The linear range was 0.5 mM-15 mM, covering the detecting range of L-lactate in clinical applications. The L-lactate biosensor had a short response time (10 s) and required only 10 μl of the sample. This L-lactate sensor modified with electrodeposited graphene had a larger sensitivity than that based on the bare SPCE. Thus, our low-cost and disposable L-lactate biosensor enhanced by graphene can perform as an attractive electrochemical device that can be manufactured for point-of-care testing (POCT) devices and be employed in POCT applications.

Development of a simple, low cost chronoamperometric assay for fructose based on a commercial graphite-nanoparticle modified screen-printed carbon electrode.

PubMed

Nicholas, Phil; Pittson, Robin; Hart, John P

2018-02-15

This paper describes the development of a simple, low cost chronoamperometric assay, for the measurement of fructose, using a graphite-nanoparticle modified screen-printed electrode (SPCE-G-COOH). Cyclic voltammetry showed that the response of the SPCE-G-COOH enhanced the sensitivity and precision, towards the enzymatically generated ferrocyanide species, over a plain SPCE; therefore the former was employed in subsequent studies. Calibration studies were carried out using chronoamperometry with a 40µl mixture containing fructose, mediator and FDH, deposited onto the SPCE-G-COOH. The response was linear from 0.1mM to 1.0mM. A commercial fruit juice sample was analysed using the developed assay and the fructose concentration was calculated to be 477mM with a precision of 3.03% (n=5). Following fortification (477mM fructose) the mean recovery was found to be 97.12% with a coefficient of variation of 6.42% (n=5); consequently, the method holds promise for the analysis of commercial fruit juices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrochemical Behavior and Determination of Chlorogenic Acid Based on Multi-Walled Carbon Nanotubes Modified Screen-Printed Electrode

PubMed Central

Ma, Xiaoyan; Yang, Hongqiao; Xiong, Huabin; Li, Xiaofen; Gao, Jinting; Gao, Yuntao

2016-01-01

In this paper, the multi-walled carbon nanotubes modified screen-printed electrode (MWCNTs/SPE) was prepared and the MWCNTs/SPE was employed for the electrochemical determination of the antioxidant substance chlorogenic acids (CGAs). A pair of well-defined redox peaks of CGA was observed at the MWCNTs/SPE in 0.10 mol/L acetic acid-sodium acetate buffer (pH 6.2) and the electrode process was adsorption-controlled. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods for the determination of CGA were proposed based on the MWCNTs/SPE. Under the optimal conditions, the proposed method exhibited linear ranges from 0.17 to 15.8 µg/mL, and the linear regression equation was Ipa (µA) = 4.1993 C (×10−5 mol/L) + 1.1039 (r = 0.9976) and the detection limit for CGA could reach 0.12 µg/mL. The recovery of matrine was 94.74%–106.65% (RSD = 2.92%) in coffee beans. The proposed method is quick, sensitive, reliable, and can be used for the determination of CGA. PMID:27801797

Ultrasensitive direct impedimetric immunosensor for detection of serum HER2.

PubMed

Sharma, Shikha; Zapatero-Rodríguez, Julia; Saxena, Rahul; O'Kennedy, Richard; Srivastava, Sudha

2018-05-30

Assesment of human epidermal growth factor receptor 2 status is a key factor prompting definitive treatment decisions that help in reducing mortality rates associated with breast cancer. In this article, highly sensitive and low-cost impedimetric immunosensor using single-chain fragment variable antibody fragments was developed for quantitative detection of human epidermal growth factor receptor 2 from serum employing gold nanoparticle-modified disposable screen-printed carbon electrodes. The gold nanoparticles facilitate fast electron transfer and offer a biocompatible surface for immobilization of small antibody fragments in an oriented manner, resulting in improved antigen binding efficiency. The single-chain fragment variable antibody fragment-modified screen printed immunosensor exhibits wide dynamic range of 0.01-100 ng mL -1 and detection limit of 0.01 ng mL -1 . The advantages offered by this platform in terms of high sensitivity, broad dynamic range and low-cost demonstrates great potential for improved monitoring of human epidermal growth factor receptor 2 levels for the management of breast and other cancers. Copyright © 2018 Elsevier B.V. All rights reserved.

Amperometric Biosensor Based on Diamine Oxidase/Platinum Nanoparticles/Graphene/Chitosan Modified Screen-Printed Carbon Electrode for Histamine Detection.

PubMed

Apetrei, Irina Mirela; Apetrei, Constantin

2016-03-24

This work describes the development and optimization studies of a novel biosensor employed in the detection and quantification of histamine in freshwater fish samples. The proposed biosensor is based on a modified carbon screen-printed electrode with diamineoxidase, graphene and platinum nanoparticles, which detects the hydrogen peroxide formed by the chemical process biocatalysed by the enzyme diamine oxidase and immobilized onto the nanostructurated surface of the receptor element. The amperometric measurements with the biosensor have been implemented in buffer solution of pH 7.4, applying an optimal low potential of +0.4 V. The novel biosensor shows high sensitivity (0.0631 μA·μM), low detection limit (2.54 × 10(-8) M) and a broad linear domain from 0.1 to 300 μM. The applicability in natural complex samples and the analytical parameters of this enzyme sensor have been performed in the quantification of histamine in freshwater fish. An excellent correlation among results achieved with the developed biosensor and results found with the standard method for all freshwater fish samples has been achieved.

3D spongy graphene-modified screen-printed sensors for the voltammetric determination of the narcotic drug codeine.

PubMed

Mohamed, Mona A; El-Gendy, Dalia M; Ahmed, Nashaat; Banks, Craig E; Allam, Nageh K

2018-03-15

Adenine-functionalized spongy graphene (FSG) composite, fabricated via a facile and green synthetic method, has been explored as a potential electrocatalyst toward the electroanalytical sensing of codeine phosphate (COD). The synthesized composite is characterized using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray powder diffraction, UV-vis absorption spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy (HRTEM), and thermogravimetric analysis. The FSG was electrically wired via modification upon screen-printed (macro electrode) sensors, which behave as a hybrid electrode material for the sensitive and selective codeine phosphate (COD) determination in the presence of paracetamol (PAR) and caffeine (CAF). The FSG- modified sensor showed an excellent electrocatalytic response towards the sensing of COD with a wide linear response range of 2.0 × 10 -8 -2.0 × 10 -4 M and a detection limit (LOD) of 5.8 × 10 -9 M, indicating its potential for the sensing of COD in clinical samples and pharmaceutical formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

Amperometric Biosensor Based on Diamine Oxidase/Platinum Nanoparticles/Graphene/Chitosan Modified Screen-Printed Carbon Electrode for Histamine Detection

PubMed Central

Apetrei, Irina Mirela; Apetrei, Constantin

2016-01-01

This work describes the development and optimization studies of a novel biosensor employed in the detection and quantification of histamine in freshwater fish samples. The proposed biosensor is based on a modified carbon screen-printed electrode with diamineoxidase, graphene and platinum nanoparticles, which detects the hydrogen peroxide formed by the chemical process biocatalysed by the enzyme diamine oxidase and immobilized onto the nanostructurated surface of the receptor element. The amperometric measurements with the biosensor have been implemented in buffer solution of pH 7.4, applying an optimal low potential of +0.4 V. The novel biosensor shows high sensitivity (0.0631 μA·μM), low detection limit (2.54 × 10−8 M) and a broad linear domain from 0.1 to 300 μM. The applicability in natural complex samples and the analytical parameters of this enzyme sensor have been performed in the quantification of histamine in freshwater fish. An excellent correlation among results achieved with the developed biosensor and results found with the standard method for all freshwater fish samples has been achieved. PMID:27023541

A highly sensitive and selective electrochemical sensor for determination of Cr(VI) in the presence of Cr(III) using modified multi-walled carbon nanotubes/quercetin screen-printed electrode.

PubMed

Sadeghi, Susan; Garmroodi, Aziz

2013-12-01

A novel screen-printed carbon electrode modified with quercetin/multi-walled carbon nanotubes was fabricated for determination of Cr(VI) in the presence of excess of Cr(III) without any pretreatment. The method is based on accumulation of the quercetin-Cr(III) complex generated in situ from Cr(VI) at the modified electrode surface in an open circuit followed by differential pulse voltammetry detection. The new method allowed selective determination of Cr(VI) in the presence of Cr(III). The influence of various parameters affecting the adsorptive stripping voltammetry performance was investigated. Under the optimum conditions, the calibration plot was found to be linear in the Cr(VI) concentration range from 1.0 to 200 μmol(-1) with a limit of detection(S/N=3) of 0.3 μmol L(-1). The relative standard deviation (RSD%) of seven replicates of the current measurements for a 50 μmol(-1) of Cr(VI) solution was 3.0%. The developed electrode displayed a very low or no sensitivity to alkali, alkali-earth and transition metal cations and was successfully applied for the determination of Cr(VI) in drinking water samples. © 2013.

A new electrochemical sensor for highly sensitive and selective detection of nitrite in food samples based on sonochemical synthesized Calcium Ferrite (CaFe2O4) clusters modified screen printed carbon electrode.

PubMed

Balasubramanian, Paramasivam; Settu, Ramki; Chen, Shen-Ming; Chen, Tse-Wei; Sharmila, Ganapathi

2018-08-15

Herein, we report a novel, disposable electrochemical sensor for the detection of nitrite ions in food samples based on the sonochemical synthesized orthorhombic CaFe 2 O 4 (CFO) clusters modified screen printed electrode. As synthesized CFO clusters were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformer infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and amperometry (i-t). Under optimal condition, the CFO modified electrode displayed a rapid current response to nitrite, a linear response range from 0.016 to 1921 µM associated with a low detection limit 6.6 nM. The suggested sensor also showed the excellent sensitivity of 3.712 μA μM -1  cm -2 . Furthermore, a good reproducibility, long-term stability and excellent selectivity were also attained on the proposed sensor. In addition, the practical applicability of the sensor was investigated via meat samples, tap water and drinking water, and showed desirable recovery rate, representing its possibilities for practical application. Copyright © 2018 Elsevier Inc. All rights reserved.

Flow injection amperometric sensor with a carbon nanotube modified screen printed electrode for determination of hydroquinone.

PubMed

Upan, Jantima; Reanpang, Preeyaporn; Chailapakul, Orawon; Jakmunee, Jaroon

2016-01-01

Flow injection amperometric (FI-Amp) sensor was developed for sensitive and selective determination of hydroquinone. A simple screen printed carbon electrode (SPCE) was modified with various nanomaterials for improvement of sensitivity on the determination of quinone. As a result, the appropriate sensitivity is obtained from the SPCE modified with carbon nanotube (CNT) which indicated that CNT contributed to the transfer of electron to quinone. The reproducibility (n=9) and repeatability (n=111) of SPCE-CNT were obtained at 4.4% and 3.6%RSD, respectively. The SPCE-CNT electrode and enzymatic column were incorporated to the FI-Amp system to determine hydroquinone. Laccase was immobilized on silica gel using a cross-linking method by glutaraldehyde modification and then packed in the column. The laccase column has high efficiency for catalytic oxidation of hydroquinone to quinone, which further detects by amperometric detection. Parameters affecting response of the proposed sensor, i.e., pH, ionic strength, and temperature have been optimized. The proposed system provided a wide linear range between 1 and 50 µM with detection limit of 0.1 µM. Satisfactory recoveries in the range of 91.2-103.8% were obtained for the analysis of water sample. Copyright © 2015 Elsevier B.V. All rights reserved.

Colorectal Cancer Screening and Chinese Americans: Efficacy of Lay Health Worker Outreach and Print Materials.

PubMed

Nguyen, Tung T; Tsoh, Janice Y; Woo, Kent; Stewart, Susan L; Le, Gem M; Burke, Adam; Gildengorin, Ginny; Pasick, Rena J; Wang, Jun; Chan, Elaine; Fung, Lei-Chun; Jih, Jane; McPhee, Stephen J

2017-03-01

Chinese Americans have low colorectal cancer (CRC) screening rates. Evidence-based interventions to increase CRC screening in this population are lacking. This study aims to compare the efficacy of two interventions in increasing CRC screening among Chinese Americans. Cluster randomized comparative trial. From 2010 to 2014, a community-academic team conducted this study in San Francisco, CA with Chinese Americans aged 50-75 years who spoke English, Cantonese, or Mandarin. Lay health worker (LHW) intervention plus in-language brochure (LHW+Print) versus brochure (Print). LHWs in the LHW+Print arm were trained to teach participants about CRC in two small group sessions and two telephone calls. Change in self-reports of ever having had CRC screening and being up to date for CRC screening from baseline to 6 months post-intervention. Statistical analysis was performed from 2014 to 2015. This study recruited 58 LHWs, who in turn recruited 725 participants. The average age of the participants was 62.2 years, with 81.1% women and 99.4% foreign born. Knowledge increase was significant (p<0.002) for nine measures in the LHW+Print group and six in the Print group. Both groups had increases in having ever been screened for CRC (LHW+Print, 73.9%-88.3%, p<0.0001; Print, 72.3%-79.5%, p=0.0003) and being up to date for CRC screening (LHW+Print, 60.0%-78.1%, p<0.0001; Print, 58.1%-64.1%, p=0.0003). In multivariable analyses, the intervention OR for LHW+Print versus Print was 1.94 (95% CI=1.34, 2.79) for ever screening and 2.02 (95% CI=1.40, 2.90) for being up to date. Both in-language print materials and LHW outreach plus print materials increased CRC screening among Chinese Americans. The combination of LHW+Print was more effective than Print alone. These findings can guide clinicians and policymakers in choosing appropriate interventions to increase CRC screening among Chinese American immigrants. This study is registered at www.clinicaltrials.gov NCT00947206. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Amperometric biosensor based on prussian blue and nafion modified screen-printed electrode for screening of potential xanthine oxidase inhibitors from medicinal plants.

PubMed

El Harrad, Loubna; Amine, Aziz

2016-04-01

A simple and sensitive amperometric biosensor was developed for the screening of potential xanthine oxidase inhibitors from medicinal plants. This biosensor was prepared by immobilization of xanthine oxidase on the surface of prussian blue modified screen-printed electrodes using nafion and glutaraldehyde. The developed biosensor showed a linear amperometric response at an applied potential of +0.05 V toward the detection of hypoxanthine from 5 μM to 45 μM with a detection limit of 0.4 μM (S/N=3) and its sensitivity was found to be 600 mA M(-1) cm(-2). In addition, the biosensor exhibited a good storage stability. The inhibition of xanthine oxidase by allopurinol was studied under the optimized conditions. The linear range of allopurinol concentration is obtained up to 2.5 μM with an estimated 50% of inhibitionI50=1.8 μM. The developed biosensor was successfully applied to the screening of xanthine oxidase inhibitors from 13 medicinal plants belonging to different families. Indeed, Moroccan people traditionally use these plants as infusion for the treatment of gout and its related symptoms. For this purpose, water extracts obtained from the infusion of these plants were used for the experiments. In this work, 13 extracts were assayed and several of them demonstrated xanthine oxidase inhibitory effect, with an inhibition greater than 50% compared to spectrophotometry measurements that only few extracts showed an inhibition greater than 50%. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of Nanoparticles on Modified Screen Printed Inhibition Superoxide Dismutase Electrodes for Aluminum

PubMed Central

Barquero-Quirós, Miriam; Arcos-Martínez, María Julia

2016-01-01

A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme superoxide dismutase has been developed. The oxidation signal of epinephrine substrate was affected by the presence of Al(III) ions leading to a decrease in its amperometric current. The immobilization of the enzyme was performed with glutaraldehyde on screen-printed carbon electrodes modifiedwith tetrathiofulvalene (TTF) and different types ofnanoparticles. Nanoparticles of gold, platinum, rhodium and palladium were deposited on screen printed carbon electrodes by means of two electrochemical procedures. Nanoparticles were characterized trough scanning electronic microscopy, X-rays fluorescence, and atomic force microscopy. Palladium nanoparticles showed lower atomic force microscopy parameters and higher slope of aluminum calibration curves and were selected to perform sensor validation. The developed biosensor has a detection limit of 2.0 ± 0.2 μM for Al(III), with a reproducibility of 7.9% (n = 5). Recovery of standard reference material spiked to buffer solution was 103.8% with a relative standard deviation of 4.8% (n = 5). Recovery of tap water spiked with the standard reference material was 100.5 with a relative standard deviation of 3.4% (n = 3). The study of interfering ions has also been carried out. PMID:27681735

Trace lead analysis based on carbon-screen-printed-electrodes modified via 4-carboxy-phenyl diazonium salt electroreduction.

PubMed

Bouden, Sarra; Chaussé, Annie; Dorbes, Stephane; El Tall, Omar; Bellakhal, Nizar; Dachraoui, Mohamed; Vautrin-Ul, Christine

2013-03-15

This paper describes the use of 4-carboxyphenyl-grafted screen-printed carbon electrodes (4-CP-SPEs) for trace lead analysis. These novel and simple use of electrodes were easily prepared by the electrochemical reduction of the corresponding diazonium salt. Pb detection was then performed by a three-steps method in order to avoid oxygen interference: (i) immersion of the grafted screen-printed electrode (SPE) in the sample and adsorption of Pb(II), (ii) reduction of adsorbed Pb(II) by chronoamperometry (CA), and (iii) oxidation of Pb by Anodic Square Wave Voltammetry (SWV). The reoxidation response was exploited for lead detection and quantification. In order to optimize the analytical responses, the influence of the adsorption medium pH and the adsorption time were investigated. Moreover, an interference study was carried out with Cu(II), Hg(II), Al(III), Mn(II), Zn(II), Cd(II) and no major interference can be expected to quantify Pb(II). The described method provided a limit of detection and a limit of quantification of 1.2 × 10(-9)M and 4.1 × 10(-9)M, respectively. These performances indicate that the 4-CP-SPE could be considered as an efficient tool for environmental analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

Phosphate Detection through a Cost-Effective Carbon Black Nanoparticle-Modified Screen-Printed Electrode Embedded in a Continuous Flow System.

PubMed

Talarico, Daria; Cinti, Stefano; Arduini, Fabiana; Amine, Aziz; Moscone, Danila; Palleschi, Giuseppe

2015-07-07

An automatable flow system for the continuous and long-term monitoring of the phosphate level has been developed using an amperometric detection method based on the use of a miniaturized sensor. This method is based on the monitoring of an electroactive complex obtained by the reaction between phosphate and molybdate that is consequently reduced at the electrode surface. The use of a screen-printed electrode modified with carbon black nanoparticles (CBNPs) leads to the quantification of the complex at low potential, because CBNPs are capable of electrocatalitically enhancing the phosphomolybdate complex reduction at +125 mV versus Ag/AgCl without fouling problems. The developed system also incorporates reagents and waste storage and is connected to a portable potentiostat for rapid detection and quantification of phosphate. Main analytical parameters, such as working potential, reagent concentration, type of cell, and flow rate, were evaluated and optimized. This system was characterized by a low detection limit (6 μM). Interference studies were carried out. Good recovery percentages comprised between 89 and 131.5% were achieved in different water sources, highlighting its suitability for field measurements.

Impedimetric Label-Free Immunosensor on Disposable Modified Screen-Printed Electrodes for Ochratoxin A

PubMed Central

Malvano, Francesca; Albanese, Donatella; Crescitelli, Alessio; Pilloton, Roberto; Esposito, Emanuela

2016-01-01

An impedimetric label-free immunosensor on disposable screen-printed carbon electrodes (SPCE) for quantitative determination of Ochratoxin A (OTA) has been developed. After modification of the SPCE surface with gold nanoparticles (AuNPs), the anti-OTA was immobilized on the working electrode through a cysteamine layer. After each coating step, the modified surfaces were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The capacitance was chosen as the best parameter that describes the reproducible change in electrical properties of the electrode surface at different OTA concentrations and it was used to investigate the analytical parameters of the developed immunosensor. Under optimized conditions, the immunosensor showed a linear relationship between 0.3 and 20 ng/mL with a low detection limit of 0.25 ng/mL, making it suitable to control OTA content in many common food products. Lastly, the immunosensor was used to measure OTA in red wine samples and the results were compared with those registered with a competitive ELISA kit. The immunosensor was sensitive to OTA lower than 2 μg/kg, which represents the lower acceptable limit of OTA established by European legislation for common food products. PMID:27376339

Impedimetric Label-Free Immunosensor on Disposable Modified Screen-Printed Electrodes for Ochratoxin A.

PubMed

Malvano, Francesca; Albanese, Donatella; Crescitelli, Alessio; Pilloton, Roberto; Esposito, Emanuela

2016-06-30

An impedimetric label-free immunosensor on disposable screen-printed carbon electrodes (SPCE) for quantitative determination of Ochratoxin A (OTA) has been developed. After modification of the SPCE surface with gold nanoparticles (AuNPs), the anti-OTA was immobilized on the working electrode through a cysteamine layer. After each coating step, the modified surfaces were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The capacitance was chosen as the best parameter that describes the reproducible change in electrical properties of the electrode surface at different OTA concentrations and it was used to investigate the analytical parameters of the developed immunosensor. Under optimized conditions, the immunosensor showed a linear relationship between 0.3 and 20 ng/mL with a low detection limit of 0.25 ng/mL, making it suitable to control OTA content in many common food products. Lastly, the immunosensor was used to measure OTA in red wine samples and the results were compared with those registered with a competitive ELISA kit. The immunosensor was sensitive to OTA lower than 2 μg/kg, which represents the lower acceptable limit of OTA established by European legislation for common food products.

Training-based descreening.

PubMed

Siddiqui, Hasib; Bouman, Charles A

2007-03-01

Conventional halftoning methods employed in electrophotographic printers tend to produce Moiré artifacts when used for printing images scanned from printed material, such as books and magazines. We present a novel approach for descreening color scanned documents aimed at providing an efficient solution to the Moiré problem in practical imaging devices, including copiers and multifunction printers. The algorithm works by combining two nonlinear image-processing techniques, resolution synthesis-based denoising (RSD), and modified smallest univalue segment assimilating nucleus (SUSAN) filtering. The RSD predictor is based on a stochastic image model whose parameters are optimized beforehand in a separate training procedure. Using the optimized parameters, RSD classifies the local window around the current pixel in the scanned image and applies filters optimized for the selected classes. The output of the RSD predictor is treated as a first-order estimate to the descreened image. The modified SUSAN filter uses the output of RSD for performing an edge-preserving smoothing on the raw scanned data and produces the final output of the descreening algorithm. Our method does not require any knowledge of the screening method, such as the screen frequency or dither matrix coefficients, that produced the printed original. The proposed scheme not only suppresses the Moiré artifacts, but, in addition, can be trained with intrinsic sharpening for deblurring scanned documents. Finally, once optimized for a periodic clustered-dot halftoning method, the same algorithm can be used to inverse halftone scanned images containing stochastic error diffusion halftone noise.

Development of an Electrochemical Immunosensor for Fumonisins Detection in Foods

PubMed Central

Kadir, Mohamad Kamal Abdul; Tothill, Ibtisam E.

2010-01-01

An electrochemical affinity sensor for the determination of fumonisins mycotoxins (Fms) using monoclonal antibody modified screen-printed gold electrode with carbon counter and silver-silver chloride pseudo-reference electrode is reported in this work. A direct competitive enzyme-linked immunosorbent assay (ELISA) was initially developed, exhibiting a detection limit of 100 µg·L-1 for fumonisins. This was then transferred to the surface of a bare gold screen-printed electrode (SPGE) and detection was performed by chronoamperometry, monitoring the reaction of 3,3’,5,5’-Tetramethylbenzidine dihydrochloride (TMB) and hydrogen peroxide (H2O2) catalysed by HRP at −100 mV potential vs. onboard Ag-AgCl pseudo-reference electrode. The immunosensor exhibited detection limit of 5 µg·L−1 fumonisins with a dynamic range from 1 µg·L−1–1000 µg·L−1. The sensor also performed well in extracted corn samples. PMID:22069591

CYP450 2B4 covalently attached to carbon and gold screen printed electrodes by diazonium salt and thiols monolayers.

PubMed

Alonso-Lomillo, M A; Yardimci, C; Domínguez-Renedo, O; Arcos-Martínez, M J

2009-02-02

An easy covalent immobilization method used to develop enzyme biosensors based on carbon and gold screen printed electrodes (SPCEs and gold SPEs) is described. The linkage of biomolecules through 4-nitrobenzenediazonium tetrafluoroborate, mercaptopropionic acid and thioctic acid monolayers has been attempted using bare SPCEs and gold SPEs, as well as gold nanoparticles (AuNPs) modified SPCEs and gold SPEs. Direct covalent attachment of Cytochrome P450 2B4 (CYP450 2B4) to the transducer has been carried out by carbodiimide and hydroxysuccinimide. Experimental variables in the immobilization process and in the chronoamperometric determination of Phenobarbital (PB) have been optimized by the experimental design methodology. Reproducibility of the different biosensors has been checked under the optimum conditions, yielding values lower than 6%. Their performances have been shown by the determination of PB in pharmaceutical drugs.

Design an aptasensor based on structure-switching aptamer on dendritic gold nanostructures/Fe3O4@SiO2/DABCO modified screen printed electrode for highly selective detection of epirubicin.

PubMed

Hashkavayi, Ayemeh Bagheri; Raoof, Jahan Bakhsh

2017-05-15

The present work describes a label free electrochemical aptasensor for selective detection of epirubicin. In this project, 5'-thiole terminated aptamer was self-assembled on carbon screen printed electrode, which modified with electrodeposited gold nanoparticles on magnetic double-charged diazoniabicyclo [2.2.2] octane dichloride silica hybrid (Fe 3 O 4 @SiO 2 /DABCO) by Au-S bond. The interactions of epirubicin with aptamer on the AuNPs/Fe 3 O 4 @SiO 2 /DABCO/SPE have been studied by cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy. Under optimized conditions, the peak current of epirubicin increased linearly with increasing epirubicin concentration, due to the switching in the aptamer conformation and formation of aptamer- epirubicin complex instead of aptamer on the modified electrode surface. The Apt/AuNPs/Fe 3 O 4 @SiO 2 /DABCO/SPE is sensitive, selective and has two linear range from 0.07µM to 1.0µM and 1.0µM to 21.0µM with a detection limit of 0.04µM. The applicability of the aptasensor was successfully assessed by determination of epirubicin in a human blood serum sample. Copyright © 2017 Elsevier B.V. All rights reserved.

A Water-Based Silver-Nanowire Screen-Print Ink for the Fabrication of Stretchable Conductors and Wearable Thin-Film Transistors.

PubMed

Liang, Jiajie; Tong, Kwing; Pei, Qibing

2016-07-01

A water-based silver-nanowire (AgNW) ink is formulated for screen printing. Screen-printed AgNW patterns have uniform sharp edges, ≈50 μm resolution, and electrical conductivity as high as 4.67 × 10(4) S cm(-1) . The screen-printed AgNW patterns are used to fabricate a stretchable composite conductor, and a fully printed and intrinsically stretchable thin-film transistor array is also realized. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of screen-printed tryptophan-kynurenine immunosensor for in vitro assay of kynurenine-mediated immunosuppression effect of cancer cells on activated T-cells.

PubMed

Karami, Pari; Majidi, Mir Reza; Johari-Ahar, Mohammad; Barar, Jaleh; Omidi, Yadollah

2017-06-15

The development of analytical methods that respond to the emerging need to perform rapid 'in situ' analyses of human metabolic pathways (HMPs) demonstrates disposable screen-printed electrodes (SPEs) as an alternative to the traditional tools. In the kynurenine pathway, one of the important HMPs, increased production of kynurenine (Kyn) as a main catabolite of tryptophan (Trp) degradation is involved in the immuno-editing process supporting cancer cells in escaping from the human immune system. In the current study, we demonstrate the development of a screen-printed potentiometric immunosensor for in vitro evaluation of Trp consumption and Kyn production controlled by cancer cells in response to the activated T-lymphocytes. To engineer this immunosensor, uniform layer of carboxylated multiwall carbon nanotubes (MWCNT) was deposited on gold screen-printed electrode (AuSPE), and afterwards monoclonal antibody (mAb) specific to l-kynurenine was covalently conjugated with the MWCNT modified AuSPE. The engineered immunosensor was examined in monitoring Trp consumption and Kyn production in metastatic (Calu-6, NCI-H1299, and HT29) and nonmetastatic (HepG2 and 1321NI) cancer cell lines. Without applying preparation and separation steps, this Trp-Kyn immunosensor offers an improved limit of detection (0.5nM and 120nM for Kyn and Trp detection, respectively) and a broad linear range of detection (LRD: 0.001-1µM and 1-100µM for Kyn, and 0.1-300µM for Trp detection). However, this immunosensor was successfully used for in situ analysis of Kyn that are produced during immuno-editing process in cell culture media, and could reveal that Trp consumption and Kyn production by highly metastatic cancer cells (HT29) were significantly higher than nonmetastatic HepG2 cancer cells. Owing to the screen-printed nature, such kind of biosensors have capability of being integrated into lab-on-a-chip (LOC), microfluidics, and micro total analysis systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Prevalence of work-related musculoskeletal injuries among South Indian hand screen-printing workers.

PubMed

Shankar, S; Naveen Kumar, R; Mohankumar, P; Jayaraman, Srinivasan

2017-01-01

Hand screen-printing (HSP) plays a predominant role in textile industries in developing countries. Workers from HSP industry were mostly affected by musculoskeletal injury due to monotonous, and prolonged work nature and poor workplace environment. The present study aims to investigate the prevalence of work-related musculoskeletal disorder (MSD) symptoms and risk factors associated among the HSP industry workers. Cochran's sample size for categorical data was used to select 385 HSP workers of 1000 samples from various provinces of Tamil Nadu, INDIA. Modified Nordic based questionnaire was used to assess the musculoskeletal injuries and risk factors among HSP workers. The statistical analysis revealed that 62.5% workers are prone to MSD symptoms with lower back (75.1%), shoulder (66.2%), knees (58.7%), and ankle/feet (55.6%). Age, experience, marital status, stress in the job were the risk factors which significantly (p < 0.05) associated with the reported MSDs. Further, this study result infers that the subjects with higher age and experience are exposed higher levels of MSD prevalence of 85.5% and 92.0% respectively in past 12 months than other groups. Among the different work categories in HSP task, the workers reported with the maximum discomfort during printing work (63.1%) with Odds ratio as 10.38 and 95% CI is 6.18-17.4. than the material handling and drying task. Study results infer that HSP workers are prone to lower back and shoulder pain followed by knees and ankle feet regions. Socio-demographic factors, awkward posture and repetitive movements contribute to cause MSD among hand screen-printing workers.

Optimization of printing techniques for electrochemical biosensors

NASA Astrophysics Data System (ADS)

Zainuddin, Ahmad Anwar; Mansor, Ahmad Fairuzabadi Mohd; Rahim, Rosminazuin Ab; Nordin, Anis Nurashikin

2017-03-01

Electrochemical biosensors show great promise for point-of-care applications due to their low cost, portability and compatibility with microfluidics. The miniature size of these sensors provides advantages in terms of sensitivity, specificity and allows them to be mass produced in arrays. The most reliable fabrication technique for these sensors is lithography followed by metal deposition using sputtering or chemical vapor deposition techniques. This technique which is usually done in the cleanroom requires expensive masking followed by deposition. Recently, cheaper printing techniques such as screen-printing and ink-jet printing have become popular due to its low cost, ease of fabrication and mask-less method. In this paper, two different printing techniques namely inkjet and screen printing are demonstrated for an electrochemical biosensor. For ink-jet printing technique, optimization of key printing parameters, such as pulse voltages, drop spacing and waveform setting, in-house temperature and cure annealing for obtaining the high quality droplets, are discussed. These factors are compared with screen-printing parameters such as mesh size, emulsion thickness, minimum spacing of lines and curing times. The reliability and reproducibility of the sensors are evaluated using scotch tape test, resistivity and profile-meter measurements. It was found that inkjet printing is superior because it is mask-less, has minimum resolution of 100 µm compared to 200 µm for screen printing and higher reproducibility rate of 90% compared to 78% for screen printing.

Recent trends in digital halftoning

NASA Astrophysics Data System (ADS)

Delabastita, Paul A.

1997-02-01

Screening is perhaps the oldest form of image processing. The word refers to the mechanical cross line screens that were used at the beginning of this century for the purpose of photomechanical reproduction. Later on, these mechanical screens were replaced by photographic contact screens that enabled significantly improved process control. In the early eighties, the optical screening on graphic arts scanners was replaced by a combination of laser optics and electronic screening. The algorithms, however, were still digital implementations of the original optical methods. The printing needs in the fast growing computer and software industry gave birth to a number of alternative printing technologies such as electrophotographic and inkjet printing. Originally these deices were only designed for printing text, but soon people started experimenting and using them for printing images. The relatively low spatial resolutions of these new devices however made complete review of 'the screening issue' necessary to achieve an acceptable image quality. In this paper a number of recent developments in screening technology are summarized. Special attention is given to the interaction that exists between a halftone screen and the printing devices on which they are rendered including the color mixing behavior. Improved screening techniques are presented that take advantage of modeling the physical behavior of the rendering device.

A novel screen-printed microfluidic paper-based electrochemical device for detection of glucose and uric acid in urine.

PubMed

Yao, Yong; Zhang, Chunsun

2016-10-01

A novel screen-printed microfluidic paper-based analytical device with all-carbon electrode-enabled electrochemical assay (SP-ACE-EC-μPAD) has been developed. The fabrication of these devices involved wax screen-printing, which was simple, low-cost and energy-efficient. The working, counter and reference electrodes were screen-printed using carbon ink on the patterned paper devices. Different wax screen-printing processes were examined and optimized, which led to an improved method with a shorter heating time (~5 s) and a lower heating temperature (75 °C). Different printing screens were examined, with a 300-mesh polyester screen yielding the highest quality wax screen-prints. The carbon electrodes were screen-printed on the μPADs and then examined using cyclic voltammetry. The analytical performance of the SP-ACE-EC-μPADs for the detection of glucose and uric acid in standard solutions was investigated. The results were reproducible, with a linear relationship [R(2) = 0.9987 (glucose) or 0.9997 (uric acid)] within the concentration range of interest, and with detection limits as low as 0.35 mM (glucose) and 0.08 mM (uric acid). To determine the clinical utility of the μPADs, chronoamperometry was used to analyze glucose and uric acid in real urine samples using the standard addition method. Our devices were able to detect the analytes of interest in complex real-world biological samples, and have the potential for use in a wide variety of applications.

Electroanalytical applications of screen-printable surfactant-induced sol-gel graphite composites

DOEpatents

Guadalupe, Ana R.; Guo, Yizhu

2001-05-15

A process for preparing sol-gel graphite composite electrodes is presented. This process preferably uses the surfactant bis(2-ethylhexyl) sulfosuccinate (AOT) and eliminates the need for a cosolvent, an acidic catalyst, a cellulose binder and a thermal curing step from prior art processes. Fabrication of screen-printed electrodes by this process provides a simple approach for electroanalytical applications in aqueous and nonaqueous solvents. Examples of applications for such composite electrodes produced from this process include biochemical sensors such as disposable, single-use glucose sensors and ligand modified composite sensors for metal ion sensitive sensors.

Printing of polymer microcapsules for enzyme immobilization on paper substrate.

PubMed

Savolainen, Anne; Zhang, Yufen; Rochefort, Dominic; Holopainen, Ulla; Erho, Tomi; Virtanen, Jouko; Smolander, Maria

2011-06-13

Poly(ethyleneimine) (PEI) microcapsules containing laccase from Trametes hirsuta (ThL) and Trametes versicolor (TvL) were printed onto paper substrate by three different methods: screen printing, rod coating, and flexo printing. Microcapsules were fabricated via interfacial polycondensation of PEI with the cross-linker sebacoyl chloride, incorporated into an ink, and printed or coated on the paper substrate. The same ink components were used for three printing methods, and it was found that laccase microcapsules were compatible with the ink. Enzymatic activity of microencapsulated TvL was maintained constant in polymer-based ink for at least eight weeks. Thick layers with high enzymatic activity were obtained when laccase-containing microcapsules were screen printed on paper substrate. Flexo printed bioactive paper showed very low activity, since by using this printing method the paper surface was not fully covered by enzyme microcapsules. Finally, screen printing provided a bioactive paper with high water-resistance and the highest enzyme lifetime.

High Efficiency, Low Cost Solar Cells Manufactured Using 'Silicon Ink' on Thin Crystalline Silicon Wafers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antoniadis, H.

Reported are the development and demonstration of a 17% efficient 25mm x 25mm crystalline Silicon solar cell and a 16% efficient 125mm x 125mm crystalline Silicon solar cell, both produced by Ink-jet printing Silicon Ink on a thin crystalline Silicon wafer. To achieve these objectives, processing approaches were developed to print the Silicon Ink in a predetermined pattern to form a high efficiency selective emitter, remove the solvents in the Silicon Ink and fuse the deposited particle Silicon films. Additionally, standard solar cell manufacturing equipment with slightly modified processes were used to complete the fabrication of the Silicon Ink highmore » efficiency solar cells. Also reported are the development and demonstration of a 18.5% efficient 125mm x 125mm monocrystalline Silicon cell, and a 17% efficient 125mm x 125mm multicrystalline Silicon cell, by utilizing high throughput Ink-jet and screen printing technologies. To achieve these objectives, Innovalight developed new high throughput processing tools to print and fuse both p and n type particle Silicon Inks in a predetermined pat-tern applied either on the front or the back of the cell. Additionally, a customized Ink-jet and screen printing systems, coupled with customized substrate handling solution, customized printing algorithms, and a customized ink drying process, in combination with a purchased turn-key line, were used to complete the high efficiency solar cells. This development work delivered a process capable of high volume producing 18.5% efficient crystalline Silicon solar cells and enabled the Innovalight to commercialize its technology by the summer of 2010.« less

Rapid Quantitative Detection of Brucella melitensis by a Label-Free Impedance Immunosensor Based on a Gold Nanoparticle-Modified Screen-Printed Carbon Electrode

PubMed Central

Wu, Haiyun; Zuo, Yueming; Cui, Chuanjin; Yang, Wei; Ma, Haili; Wang, Xiaowen

2013-01-01

A rapid and simple method for quantitative monitoring of Brucella melitensis using electrochemical impedance spectroscopy (EIS) is reported for the first time. The label-free immunosensors were fabricated by immobilizing Brucella melitensis antibody on the surface of gold nanoparticle-modified screen-printed carbon electrodes (GNP-SPCEs). Cyclic voltammetry (CV) and EIS were used to characterize the Brucella melitensis antigen interaction on the surface of GNP-SPCEs with antibody. A general electronic equivalent model of an electrochemical cell was introduced for interpretation of the impedance components of the system. The results showed that the change in electron-transfer resistance (Rct) was significantly different due to the binding of Brucella melitensis cells. A linear relationship between the Rct variation and logarithmic value of the cell concentration was found from 4 × 104 to 4 × 106 CFU/mL in pure culture. The label-free impedance biosensor was able to detect as low as 1 × 104 and 4 × 105 CFU/mL of Brucella melitensis in pure culture and milk samples, respectively, in less than 1.5 h. Moreover, a good selectivity versus Escherichia coli O157:H7 and Staphylococcus aureus cells was obtained for our developed immunosensor demonstrating its specificity towards only Brucella melitensis. PMID:23881126

Fully Screen-Printed, Large-Area, and Flexible Active-Matrix Electrochromic Displays Using Carbon Nanotube Thin-Film Transistors.

PubMed

Cao, Xuan; Lau, Christian; Liu, Yihang; Wu, Fanqi; Gui, Hui; Liu, Qingzhou; Ma, Yuqiang; Wan, Haochuan; Amer, Moh R; Zhou, Chongwu

2016-11-22

Semiconducting single-wall carbon nanotubes are ideal semiconductors for printed electronics due to their advantageous electrical and mechanical properties, intrinsic printability in solution, and desirable stability in air. However, fully printed, large-area, high-performance, and flexible carbon nanotube active-matrix backplanes are still difficult to realize for future displays and sensing applications. Here, we report fully screen-printed active-matrix electrochromic displays employing carbon nanotube thin-film transistors. Our fully printed backplane shows high electrical performance with mobility of 3.92 ± 1.08 cm 2 V -1 s -1 , on-off current ratio I on /I off ∼ 10 4 , and good uniformity. The printed backplane was then monolithically integrated with an array of printed electrochromic pixels, resulting in an entirely screen-printed active-matrix electrochromic display (AMECD) with good switching characteristics, facile manufacturing, and long-term stability. Overall, our fully screen-printed AMECD is promising for the mass production of large-area and low-cost flexible displays for applications such as disposable tags, medical electronics, and smart home appliances.

Recycling Metals from Spent Screen-Printed Electrodes While Learning the Fundamentals of Electrochemical Sensing

ERIC Educational Resources Information Center

González-Sánchez, María-Isabel; Gómez-Monedero, Beatriz; Agrisuelas, Jerónimo; Valero, Edelmira

2018-01-01

A laboratory experiment in which students recycle silver and platinum selectively from spent screen-printed platinum electrodes is described. The recovered silver in solution is used to show its spontaneous redox reaction with a copper sheet. The recovered platinum is electrodeposited onto a screen-printed carbon electrode to develop a sensor for…

78 FR 12716 - Laminated Woven Sacks From the People's Republic of China: Negative Final Determination of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-25

... colors printed in register at two different print stations. However, the artwork, by use of a screen...-circumvention inquiry is laminated woven sacks produced with two ink colors printed in register and a screening... have adapted the screening process to create graphics that appear to have three or more distinct colors...

Screen-printed back-to-back electroanalytical sensors.

PubMed

Metters, Jonathan P; Randviir, Edward P; Banks, Craig E

2014-11-07

We introduce the concept of screen-printed back-to-back electroanalytical sensors where in this facile and generic approach, screen-printed electrodes are printed back-to-back with a common electrical connection to the two working electrodes with the counter and reference electrodes for each connected in the same manner as a normal "traditional" screen-printed sensor would be. This approach utilises the usually redundant back of the screen-printed sensor, converting this "dead-space" into a further electrochemical sensor which results in improvements in the analytical performance. In the use of the back-to-back design, the electrode area is consequently doubled with improvements in the analytical performance observed with the analytical sensitivity (gradient of a plot of peak height/analytical signal against concentration) doubling and the corresponding limit-of-detection being reduced. We also demonstrate that through intelligent electrode design, a quadruple in the observed analytical sensitivity can also be realised when double microband electrodes are used in the back-to-back configuration as long as they are placed sufficiently apart such that no diffusional interaction occurs. Such work is generic in nature and can be facilely applied to a plethora of screen-printed (and related) sensors utilising the commonly overlooked redundant back of the electrode providing facile improvements in the electroanalytical performance.

Standard Printing Screen System.

DTIC Science & Technology

area pattern screens. It also describes the creation of a 100-step continuous growth halftone scale for the purpose of specifying quality control tolerances of screen tints for the printed product. (Author)

Understanding wax screen-printing: a novel patterning process for microfluidic cloth-based analytical devices.

PubMed

Liu, Min; Zhang, Chunsun; Liu, Feifei

2015-09-03

In this work, we first introduce the fabrication of microfluidic cloth-based analytical devices (μCADs) using a wax screen-printing approach that is suitable for simple, inexpensive, rapid, low-energy-consumption and high-throughput preparation of cloth-based analytical devices. We have carried out a detailed study on the wax screen-printing of μCADs and have obtained some interesting results. Firstly, an analytical model is established for the spreading of molten wax in cloth. Secondly, a new wax screen-printing process has been proposed for fabricating μCADs, where the melting of wax into the cloth is much faster (∼5 s) and the heating temperature is much lower (75 °C). Thirdly, the experimental results show that the patterning effects of the proposed wax screen-printing method depend to a certain extent on types of screens, wax melting temperatures and melting time. Under optimized conditions, the minimum printing width of hydrophobic wax barrier and hydrophilic channel is 100 μm and 1.9 mm, respectively. Importantly, the developed analytical model is also well validated by these experiments. Fourthly, the μCADs fabricated by the presented wax screen-printing method are used to perform a proof-of-concept assay of glucose or protein in artificial urine with rapid high-throughput detection taking place on a 48-chamber cloth-based device and being performed by a visual readout. Overall, the developed cloth-based wax screen-printing and arrayed μCADs should provide a new research direction in the development of advanced sensor arrays for detection of a series of analytes relevant to many diverse applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Detection of Antibiotics and Evaluation of Antibacterial Activity with Screen-Printed Electrodes

PubMed Central

Titoiu, Ana Maria; Marty, Jean-Louis

2018-01-01

This review provides a brief overview of the fabrication and properties of screen-printed electrodes and details the different opportunities to apply them for the detection of antibiotics, detection of bacteria and antibiotic susceptibility. Among the alternative approaches to costly chromatographic or ELISA methods for antibiotics detection and to lengthy culture methods for bacteria detection, electrochemical biosensors based on screen-printed electrodes present some distinctive advantages. Chemical and (bio)sensors for the detection of antibiotics and assays coupling detection with screen-printed electrodes with immunomagnetic separation are described. With regards to detection of bacteria, the emphasis is placed on applications targeting viable bacterial cells. While the electrochemical sensors and biosensors face many challenges before replacing standard analysis methods, the potential of screen-printed electrodes is increasingly exploited and more applications are anticipated to advance towards commercial analytical tools. PMID:29562637

Thin-Film Thermoelectric Module for Power Generator Applications Using a Screen-Printing Method

NASA Astrophysics Data System (ADS)

Lee, Heon-Bok; Yang, Hyun Jeong; We, Ju Hyung; Kim, Kukjoo; Choi, Kyung Cheol; Cho, Byung Jin

2011-05-01

A new process for fabricating a low-cost thermoelectric module using a screen-printing method has been developed. Thermoelectric properties of screen-printed ZnSb films were investigated in an effort to develop a thermoelectric module with low cost per watt. The screen-printed Zn x Sb1- x films showed a low carrier concentration and high Seebeck coefficient when x was in the range of 0.5 to 0.57 and the annealing temperature was kept below 550°C. When the annealing temperature was higher than 550°C, the carrier concentration of the Zn x Sb1- x films reached that of a metal, leading to a decrease of the Seebeck coefficient. In the present experiment, the optimized carrier concentration of screen-printed ZnSb was 7 × 1018/cm3. The output voltage and power density of the ZnSb film were 10 mV and 0.17 mW/cm2, respectively, at Δ T = 50 K. A thermoelectric module was produced using the proposed screen-printing approach with ZnSb and CoSb3 as p-type and n-type thermoelectric materials, respectively, and copper as the pad metal.

One Step Assembly of Thin Films of Carbon Nanotubes on Screen Printed Interface for Electrochemical Aptasensing of Breast Cancer Biomarker.

PubMed

Nawaz, Muhammad Azhar Hayat; Rauf, Sajid; Catanante, Gaelle; Nawaz, Mian Hasnain; Nunes, Gilvanda; Marty, Jean Louis; Hayat, Akhtar

2016-10-06

Thin films of organic moiety functionalized carbon nanotubes (CNTs) from a very well-dispersed aqueous solution were designed on a screen printed transducer surface through a single step directed assembly methodology. Very high density of CNTs was obtained on the screen printed electrode surface, with the formation of a thin and uniform layer on transducer substrate. Functionalized CNTs were characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Brunauer-Emmett- Teller (BET) surface area analyzer methodologies, while CNT coated screen printed transducer platform was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed methodology makes use of a minimum amount of CNTs and toxic solvents, and is successfully demonstrated to form thin films over macroscopic areas of screen printed carbon transducer surface. The CNT coated screen printed transducer surface was integrated in the fabrication of electrochemical aptasensors for breast cancer biomarker analysis. This CNT coated platform can be applied to immobilize enzymes, antibodies and DNA in the construction of biosensor for a broad spectrum of applications.

One Step Assembly of Thin Films of Carbon Nanotubes on Screen Printed Interface for Electrochemical Aptasensing of Breast Cancer Biomarker

PubMed Central

Nawaz, Muhammad Azhar Hayat; Rauf, Sajid; Catanante, Gaelle; Nawaz, Mian Hasnain; Nunes, Gilvanda; Louis Marty, Jean; Hayat, Akhtar

2016-01-01

Thin films of organic moiety functionalized carbon nanotubes (CNTs) from a very well-dispersed aqueous solution were designed on a screen printed transducer surface through a single step directed assembly methodology. Very high density of CNTs was obtained on the screen printed electrode surface, with the formation of a thin and uniform layer on transducer substrate. Functionalized CNTs were characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) surface area analyzer methodologies, while CNT coated screen printed transducer platform was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed methodology makes use of a minimum amount of CNTs and toxic solvents, and is successfully demonstrated to form thin films over macroscopic areas of screen printed carbon transducer surface. The CNT coated screen printed transducer surface was integrated in the fabrication of electrochemical aptasensors for breast cancer biomarker analysis. This CNT coated platform can be applied to immobilize enzymes, antibodies and DNA in the construction of biosensor for a broad spectrum of applications. PMID:27782067

High-resolution microcontact printing and transfer of massive arrays of microorganisms on planar and compartmentalized nanoporous aluminium oxide.

PubMed

Ingham, Colin; Bomer, Johan; Sprenkels, Ad; van den Berg, Albert; de Vos, Willem; van Hylckama Vlieg, Johan

2010-06-07

Handling microorganisms in high throughput and their deployment into miniaturized platforms presents significant challenges. Contact printing can be used to create dense arrays of viable microorganisms. Such "living arrays", potentially with multiple identical replicates, are useful in the selection of improved industrial microorganisms, screening antimicrobials, clinical diagnostics, strain storage, and for research into microbial genetics. A high throughput method to print microorganisms at high density was devised, employing a microscope and a stamp with a massive array of PDMS pins. Viable bacteria (Lactobacillus plantarum, Esherichia coli), yeast (Candida albicans) and fungal spores (Aspergillus fumigatus) were deposited onto porous aluminium oxide (PAO) using arrays of pins with areas from 5 x 5 to 20 x 20 microm. Printing onto PAO with up to 8100 pins of 20 x 20 microm area with 3 replicates was achieved. Printing with up to 200 pins onto PAO culture chips (divided into 40 x 40 microm culture areas) allowed inoculation followed by effective segregation of microcolonies during outgrowth. Additionally, it was possible to print mixtures of C. albicans and spores of A. fumigatus with a degree of selectivity by capture onto a chemically modified PAO surface. High resolution printing of microorganisms within segregated compartments and on functionalized PAO surfaces has significant advantages over what is possible on semi-solid surfaces such as agar.

Low-cost and disposable sensors for the simultaneous determination of coenzyme Q10 and α-lipoic acid using manganese (IV) oxide-modified screen-printed graphene electrodes.

PubMed

Charoenkitamorn, Kanokwan; Chaiyo, Sudkate; Chailapakul, Orawon; Siangproh, Weena

2018-04-03

In this work, for the first time, manganese (IV) oxide-modified screen-printed graphene electrodes (MnO 2 /SPGEs) were developed for the simultaneous electrochemical detection of coenzyme Q10 (CoQ10) and α-lipoic acid (ALA). This sensor exhibits attractive benefits such as simplicity, low production costs, and disposability. Cyclic voltammetry (CV) was used to characterize the electrochemical behavior of the analyte and investigate the capacitance and electroactive surface area of the unmodified and modified electrode surfaces. The electrochemical behavior of CoQ10 and ALA on MnO 2 /SPGEs was also discussed. Additionally, square wave anodic stripping voltammetry (SWASV) was used for the quantitative determination of CoQ10 and ALA. Under optimal conditions, the obtained signals are linear in the concentration range from 2.0 to 75.0 μg mL -1 for CoQ10 and 0.3-25.0 μg mL -1 for ALA. The low limits of detection (LODs) were found to be 0.56 μg mL -1 and 0.088 μg mL -1 for CoQ10 and ALA, respectively. Moreover, we demonstrated the utility and applicability of the MnO 2 /SPGE sensor through simultaneous measurements of CoQ10 and ALA in dietary supplements. The sensor provides high accuracy measurements, exhibiting its high potential for practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Lay health educators and print materials for the promotion of colorectal cancer screening among Korean Americans: A randomized comparative effectiveness study.

PubMed

Jo, Angela M; Nguyen, Tung T; Stewart, Susan; Sung, Min J; Gildengorin, Ginny; Tsoh, Janice Y; Tong, Elisa K; Lo, Penny; Cuaresma, Charlene; Sy, Angela; Lam, Hy; Wong, Ching; Jeong, Matthew; Chen, Moon S; Kagawa-Singer, Marjorie

2017-07-15

Colorectal cancer (CRC) is the second most commonly diagnosed cancer among Korean American men and women. Although CRC screening is effective in reducing the burden of this disease, studies have shown that Korean Americans have low screening rates. The authors conducted a 2-arm cluster randomized controlled trial comparing a brochure (print) with a brochure and lay health educator (LHE) outreach (print + LHE) in increasing CRC screening rates among Korean American individuals. Self-administered written surveys at baseline and at 6 months assessed knowledge of CRC and its screening, ever screening, and being up to date with screening. A total of 28 LHEs recruited 348 participants aged 50 to 75 years from their social networks. Significant percentages of participants reported not having health insurance (29.3%) or a usual source of care (35.6%). At 6 months postintervention, the print + LHE participants had a greater increase in knowledge compared with those in the print arm (P = .0013). In multivariable analyses, both groups had significant increases in ever screening (print plus LHE: odds ratio [OR], 1.60 [95% confidence interval (95% CI), 1.26-2.03] and print: OR, 1.42 [95% CI, 1.10-1.82]) and being up to date with screening (print plus LHE: OR, 1.63 [95% CI, 1.23-2.16] and print: OR, 1.40 [95% CI, 1.04-1.89]). However, these increases did not differ significantly between the study arms. Having insurance and having seen a provider within the past year were found to be positively associated with screening. Compared with a brochure, LHE outreach yielded greater increases in knowledge but resulted in similar increases in CRC screening in a Korean American population with barriers to health care access. More work is needed to appropriately address logistical and system barriers in this community. Cancer 2017;123:2705-15. © 2017 American Cancer Society. © 2017 American Cancer Society.

Stretching Screens and Imaginations.

ERIC Educational Resources Information Center

Douthwaite, Shelaugh

1983-01-01

Secondary students utilize a simplified technique to make silk screen prints, which can be printed onto T-shirts. The only materials needed from art suppliers are a few squeegees and a few yards of polyester screen mesh. (RM)

Dispenser printed electroluminescent lamps on textiles for smart fabric applications

NASA Astrophysics Data System (ADS)

de Vos, Marc; Torah, Russel; Tudor, John

2016-04-01

Flexible electroluminescent (EL) lamps are fabricated onto woven textiles using a novel dispenser printing process. Dispenser printing utilizes pressurized air to deposit ink onto a substrate through a syringe and nozzle. This work demonstrates the first use of this technology to fabricate EL lamps. The luminance of the dispenser printed EL lamps is compared to screen-printed EL lamps, both printed on textile, and also commercial EL lamps on polyurethane film. The dispenser printed lamps are shown to have a 1.5 times higher luminance than the best performing commercially available lamp, and have a comparable performance to the screen-printed lamps.

Determination of the Electrochemical Area of Screen-Printed Electrochemical Sensing Platforms.

PubMed

García-Miranda Ferrari, Alejandro; Foster, Christopher W; Kelly, Peter J; Brownson, Dale A C; Banks, Craig E

2018-06-08

Screen-printed electrochemical sensing platforms, due to their scales of economy and high reproducibility, can provide a useful approach to translate laboratory-based electrochemistry into the field. An important factor when utilising screen-printed electrodes (SPEs) is the determination of their real electrochemical surface area, which allows for the benchmarking of these SPEs and is an important parameter in quality control. In this paper, we consider the use of cyclic voltammetry and chronocoulometry to allow for the determination of the real electrochemical area of screen-printed electrochemical sensing platforms, highlighting to experimentalists the various parameters that need to be diligently considered and controlled in order to obtain useful measurements of the real electroactive area.

A Wireless Sensor System for Real-Time Measurement of Pressure Profiles at Lower Limb Protheses to Ensure Proper Fitting

DTIC Science & Technology

2011-10-01

been developed. The next step is to develop a the base technology into a grid like mapping sensor, construct the excitation and detection circuits...the project involves advancing the base technology into a grid -like mapping se nsor, constructing the excitation and detection circuits, modifying and...further. In conclusion, the screen printing and etching process allows for precise repeat able production of sensing elements for grid fabrication

Stabilization of electrogenerated copper species on electrodes modified with quantum dots.

PubMed

Martín-Yerga, Daniel; Costa-García, Agustín

2017-02-15

Quantum dots (QDs) have special optical, surface, and electronic properties that make them useful for electrochemical applications. In this work, the electrochemical behavior of copper in ammonia medium is described using bare screen-printed carbon electrodes and the same modified with CdSe/ZnS QDs. At the bare electrodes, the electrogenerated Cu(i) and Cu(0) species are oxidized by dissolved oxygen in a fast coupled chemical reaction, while at the QDs-modified electrode, the re-oxidation of Cu(i) and Cu(0) species can be observed, which indicates that they are stabilized by the nanocrystals present on the electrode surface. A weak adsorption is proposed as the main cause for this stabilization. The electrodeposition on electrodes modified with QDs allows the generation of random nanostructures with copper nanoparticles, avoiding the preferential nucleation onto the most active electrode areas.

Rapid quantitative detection of Brucella melitensis by a label-free impedance immunosensor based on a gold nanoparticle-modified screen-printed carbon electrode.

PubMed

Wu, Haiyun; Zuo, Yueming; Cui, Chuanjin; Yang, Wei; Ma, Haili; Wang, Xiaowen

2013-07-04

A rapid and simple method for quantitative monitoring of Brucella melitensis using electrochemical impedance spectroscopy (EIS) is reported for the first time. The label-free immunosensors were fabricated by immobilizing Brucella melitensis antibody on the surface of gold nanoparticle-modified screen-printed carbon electrodes (GNP-SPCEs). Cyclic voltammetry (CV) and EIS were used to characterize the Brucella melitensis antigen interaction on the surface of GNP-SPCEs with antibody. A general electronic equivalent model of an electrochemical cell was introduced for interpretation of the impedance components of the system. The results showed that the change in electron-transfer resistance (Rct) was significantly different due to the binding of Brucella melitensis cells. A linear relationship between the Rct variation and logarithmic value of the cell concentration was found from 4 × 10(4) to 4 × 10(6) CFU/mL in pure culture. The label-free impedance biosensor was able to detect as low as 1 × 10(4) and 4 × 10(5) CFU/mL of Brucella melitensis in pure culture and milk samples, respectively, in less than 1.5 h. Moreover, a good selectivity versus Escherichia coli O157:H7 and Staphylococcus aureus cells was obtained for our developed immunosensor demonstrating its specificity towards only Brucella melitensis.

Electrochemical DNA biosensor for bovine papillomavirus detection using polymeric film on screen-printed electrode.

PubMed

Nascimento, Gustavo A; Souza, Elaine V M; Campos-Ferreira, Danielly S; Arruda, Mariana S; Castelletti, Carlos H M; Wanderley, Marcela S O; Ekert, Marek H F; Bruneska, Danyelly; Lima-Filho, José L

2012-01-01

A new electrochemical DNA biosensor for bovine papillomavirus (BPV) detection that was based on screen-printed electrodes was comprehensively studied by electrochemical methods of cyclic voltammetry (CV) and differential pulse voltammetry (DPV). A BPV probe was immobilised on a working electrode (gold) modified with a polymeric film of poly-L-lysine (PLL) and chitosan. The experimental design was carried out to evaluate the influence of polymers, probe concentration (BPV probe) and immobilisation time on the electrochemical reduction of methylene blue (MB). The polymer poly-L-lysine (PLL), a probe concentration of 1 μM and an immobilisation time of 60 min showed the best result for the BPV probe immobilisation. With the hybridisation of a complementary target sequence (BPV target), the electrochemical signal decreased compared to a BPV probe immobilised on the modified PLL-gold electrode. Viral DNA that was extracted from cattle with papillomatosis also showed a decrease in the MB electrochemical reduction, which suggested that the decreased electrochemical signal corresponded to a bovine papillomavirus infection. The hybridisation specificity experiments further indicated that the biosensor could discriminate the complementary sequence from the non-complementary sequence. Thus, the results showed that the development of analytical devices, such as a biosensor, could assist in the rapid and efficient detection of bovine papillomavirus DNA and help in the prevention and treatment of papillomatosis in cattle. Copyright © 2012 Elsevier B.V. All rights reserved.

Stabilization of glucose-oxidase in the graphene paste for screen-printed glucose biosensor

NASA Astrophysics Data System (ADS)

Pepłowski, Andrzej; Janczak, Daniel; Jakubowska, Małgorzata

2015-09-01

Various methods and materials for enzyme stabilization within screen-printed graphene sensor were analyzed. Main goal was to develop technology allowing immediate printing of the biosensors in single printing process. Factors being considered were: toxicity of the materials used, ability of the material to be screen-printed (squeezed through the printing mesh) and temperatures required in the fabrication process. Performance of the examined sensors was measured using chemical amperometry method, then appropriate analysis of the measurements was conducted. The analysis results were then compared with the medical requirements. Parameters calculated were: correlation coefficient between concentration of the analyte and the measured electrical current (0.986) and variation coefficient for the particular concentrations of the analyte used as the calibration points. Variation of the measured values was significant only in ranges close to 0, decreasing for the concentrations of clinical importance. These outcomes justify further development of the graphene-based biosensors fabricated through printing techniques.

Electroanalytical sensing of chromium(III) and (VI) utilising gold screen printed macro electrodes.

PubMed

Metters, Jonathan P; Kadara, Rashid O; Banks, Craig E

2012-02-21

We report the fabrication of gold screen printed macro electrodes which are electrochemically characterised and contrasted to polycrystalline gold macroelectrodes with their potential analytical application towards the sensing of chromium(III) and (VI) critically explored. It is found that while these gold screen printed macro electrodes have electrode kinetics typically one order of magnitude lower than polycrystalline gold macroelectrodes as is measured via a standard redox probe, in terms of analytical sensing, these gold screen printed macro electrodes mimic polycrystalline gold in terms of their analytical performance towards the sensing of chromium(III) and (VI), whilst boasting additional advantages over the macro electrode due to their disposable one-shot nature and the ease of mass production. An additional advantage of these gold screen printed macro electrodes compared to polycrystalline gold is the alleviation of the requirement to potential cycle the latter to form the required gold oxide which aids in the simplification of the analytical protocol. We demonstrate that gold screen printed macro electrodes allow the low micro-molar sensing of chromium(VI) in aqueous solutions over the range 10 to 1600 μM with a limit of detection (3σ) of 4.4 μM. The feasibility of the analytical protocol is also tested through chromium(VI) detection in environmental samples.

Entirely screen printed CdS/CdTe solar cell

NASA Astrophysics Data System (ADS)

Ikegami, S.; Matsumoto, H.; Uda, H.; Komatsu, Y.; Nakano, A.; Kuribayashi, K.

An entirely screen printed CdS/CdTe solar cell has been manufactured on a borosilicate glass substrate by successively repeating screen printing and heating in a belt furnace of each paste of CdS, Cd+Te, C, Ag+In and Ag. In a small cell with 0.78 sq cm area, the intrinsic conversion efficiency of 12.8 percent has been obtained; this value is the highest in the thin film type solar cells. On a large glass substrate of 30 x 30 sq cm, 28 unit solar cells connected in series have been constructed by this printing technique, their intrinsic efficiency being 8.5 percent. Under the roof top condition, no change in output power is observed in the present solar cells encapsulated over 206 days. Thus, the entirely screen printed CdS/CdTe solar cells can be expected as low cost, highly efficient, and stable solar cells.

PERSONAL COMPUTER MONITORS: A SCREENING EVALUATION OF VOLATILE ORGANIC EMISSIONS FROM EXISTING PRINTED CIRCUIT BOARD LAMINATES AND POTENTIAL POLLUTION PREVENTION ALTERNATIVES

EPA Science Inventory

The report gives results of a screening evaluation of volatile organic emissions from printed circuit board laminates and potential pollution prevention alternatives. In the evaluation, printed circuit board laminates, without circuitry, commonly found in personal computer (PC) m...

Structural and optical characterization of NiSe film grown by screen-printing method

NASA Astrophysics Data System (ADS)

Sharma, Kapil; Sharma, D. K.; Dwivedi, D. K.; Kumar, Vipin

2018-05-01

In present investigation NiSe films were grown by economical screen-printing method. Optimum conditions for growing good quality screen-printed films were found. The films were characterized for their structural and optical properties. The polycrystalline nature of films with hexagonal structure was confirmed through XRD analysis. Direct type of optical band gap of 1.75 eV for the NiSe film was confirmed by optical characterization.

Alternate methods of applying diffusants to silicon solar cells. [screen printing of thick-film paste materials and vapor phase transport from solid sources

NASA Technical Reports Server (NTRS)

Brock, T. W.; Field, M. B.

1979-01-01

Low-melting phosphate and borate glasses were screen printed on silicon wafers and heated to form n and p junctions. Data on surface appearance, sheet resistance and junction depth are presented. Similar data are reported for vapor phase transport from sintered aluminum metaphosphate and boron-containing glass-ceramic solid sources. Simultaneous diffusion of an N(+) layer with screen-printed glass and a p(+) layer with screen-printed Al alloy paste was attempted. No p(+) back surface field formation was achieved. Some good cells were produced but the heating in an endless-belt furnace caused a large scatter in sheet resistance and junction depth for three separate lots of wafers.

Challenges and the state of the technology for printed sensor arrays for structural monitoring

NASA Astrophysics Data System (ADS)

Joshi, Shiv; Bland, Scott; DeMott, Robert; Anderson, Nickolas; Jursich, Gregory

2017-04-01

Printed sensor arrays are attractive for reliable, low-cost, and large-area mapping of structural systems. These sensor arrays can be printed on flexible substrates or directly on monitored structural parts. This technology is sought for continuous or on-demand real-time diagnosis and prognosis of complex structural components. In the past decade, many innovative technologies and functional materials have been explored to develop printed electronics and sensors. For example, an all-printed strain sensor array is a recent example of a low-cost, flexible and light-weight system that provides a reliable method for monitoring the state of aircraft structural parts. Among all-printing techniques, screen and inkjet printing methods are well suited for smaller-scale prototyping and have drawn much interest due to maturity of printing procedures and availability of compatible inks and substrates. Screen printing relies on a mask (screen) to transfer a pattern onto a substrate. Screen printing is widely used because of the high printing speed, large selection of ink/substrate materials, and capability of making complex multilayer devices. The complexity of collecting signals from a large number of sensors over a large area necessitates signal multiplexing electronics that need to be printed on flexible substrate or structure. As a result, these components are subjected to same deformation, temperature and other parameters for which sensor arrays are designed. The characteristics of these electronic components, such as transistors, are affected by deformation and other environmental parameters which can lead to erroneous sensed parameters. The manufacturing and functional challenges of the technology of printed sensor array systems for structural state monitoring are the focus of this presentation. Specific examples of strain sensor arrays will be presented to highlight the technical challenges.

Septonex-tetraphenylborate screen-printed ion selective electrode for the potentiometric determination of Septonex in pharmaceutical preparations.

PubMed

Mohamed, Gehad G; El-Shahat, M F; Al-Sabagh, A M; Migahed, M A; Ali, Tamer Awad

2011-04-07

A screen-printed electrode (SPE) was fabricated for the determination of 1-(ethoxycarbonyl)pentadecyltrimethylammonium bromide (Septonex) based on the use of Septonex-tetraphenylborate as the electroactive substance, and o-nitrophenyloctylether (o-NPOE) as the plasticizing agent. The electrode passes a near-Nernstian cationic slope of 59.33 ± 0.85 mV from activity between pH values of 2 to 9 with a lower detection limit of 9×10(-7) M and response time of about 5 s and exhibits an adequate shelf-life of 6 months. The method was applied for the determination of Septonex in pharmaceutical preparations. A percentage recovery of 99.88% was obtained with RSD=1.24%. The electrode was successfully applied in the determination of Septonex in laboratory-prepared samples by direct potentiometric, calibration curve and standard addition methods. Potentiometric titration of Septonex with sodium tetraphenylborate and phosphotungstic acid as a titrant was monitored with the modified screen-printed electrode as an end-point indicator electrode. Selectivity coefficients for Septonex relative to a number of potential interfering substances were determined. The sensor was highly selective for Septonex over a large number of compounds. Selectivity coefficient data for some common ions show negligible interference; however, cetyltrimethylammonium bromide and iodide ions interfere significantly. The analytical usefulness of the proposed electrode was evaluated by its application in the determination of Septonex in laboratory-prepared pharmaceutical samples with satisfactory results. The results obtained with the fabricated sensor are comparable with those obtained by the British Pharmacopeia method. © The Royal Society of Chemistry 2011

A novel screen-printed mast cell-based electrochemical sensor for detecting spoilage bacterial quorum signaling molecules (N-acyl-homoserine-lactones) in freshwater fish.

PubMed

Jiang, Donglei; Liu, Yan; Jiang, Hui; Rao, Shengqi; Fang, Wu; Wu, Mangang; Yuan, Limin; Fang, Weiming

2018-04-15

A novel screen-printed cell-based electrochemical sensor was developed to assess bacterial quorum signaling molecules, N-acylhomoserine lactones (AHLs). Screen-printed carbon electrode (SPCE), which possesses excellent properties such as low-cost, disposable and energy-efficient, was modified with multi-walled carbon nanotubes (MWNTs) to improve electrochemical signals and enhance the sensitivity. Rat basophilic leukemia (RBL-2H3) mast cells encapsulated in alginate/graphene oxide (NaAgl/GO) hydrogel were immobilized on the MWNTs/SPCE to serve as recognition element. Electrochemical impedance spectroscopy (EIS) was employed to record the cell impedance signal as-influenced by Pseudomonas aeruginosa quorum-sensing molecule, N-3-oxododecanoyl homoserine lactone (3OC 12 -HSL). Experimental results show that 3OC 12 -HSL caused a significant decrease in cell viability in a dose dependent manner. The EIS value decreased with concentrations of 3OC 12 -HSL in the range of 0.1-1μM, and the detection limit for 3OC 12 -HSL was calculated to be 0.094μM. These results were confirmed via cell viability, SEM, TEM analysis. Next, the sensor was successfully applied to monitoring the production of AHLs by spoilage bacteria in three different freshwater fish juice samples which efficiently proved the practicability of this cell based method. Therefore, the proposed cell sensor may serve as an innovative and effective approach to the measurement of quorum signaling molecule and thus provides a new avenue for real-time monitoring the spoilage bacteria in freshwater fish production. Copyright © 2017 Elsevier B.V. All rights reserved.

Decoration of multi-walled carbon nanotubes with metal nanoparticles in supercritical carbon dioxide medium as a novel approach for the modification of screen-printed electrodes.

PubMed

Moreno, Virginia; Llorent-Martínez, Eulogio J; Zougagh, Mohammed; Ríos, Angel

2016-12-01

A supercritical carbon dioxide medium was used for the decoration of functionalized multi-walled carbon nanotubes (MWCNTs) with metallic nanoparticles. This procedure allowed the rapid and simple decoration of carbon nanotubes with the selected metallic nanoparticles. The prepared nanomaterials were used to modify screen-printed electrodes, improving their electrochemical properties and allowing to obtain a wide range of working electrodes based on carbon nanotubes. These electrodes were applied to the amperometric determination of vitamin B6 in food and pharmaceutical samples as an example of the analytical potentiality of the electrodes thus prepared. Using Ru-nanoparticles-MWCNTs as the working electrode, a linear dynamic range between 2.6×10 -6 and 2×10 -4 molL -1 and a limit of detection of 0.8×10 -6 molL -1 were obtained. These parameters represented a minimum 3-fold increase in sensitivity compared to the use of bare MWCNTs or other carbon-based working electrodes. Copyright © 2016 Elsevier B.V. All rights reserved.

High-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals.

PubMed

Varghese, Tony; Hollar, Courtney; Richardson, Joseph; Kempf, Nicholas; Han, Chao; Gamarachchi, Pasindu; Estrada, David; Mehta, Rutvik J; Zhang, Yanliang

2016-09-12

Screen printing allows for direct conversion of thermoelectric nanocrystals into flexible energy harvesters and coolers. However, obtaining flexible thermoelectric materials with high figure of merit ZT through printing is an exacting challenge due to the difficulties to synthesize high-performance thermoelectric inks and the poor density and electrical conductivity of the printed films. Here, we demonstrate high-performance flexible films and devices by screen printing bismuth telluride based nanocrystal inks synthesized using a microwave-stimulated wet-chemical method. Thermoelectric films of several tens of microns thickness were screen printed onto a flexible polyimide substrate followed by cold compaction and sintering. The n-type films demonstrate a peak ZT of 0.43 along with superior flexibility, which is among the highest reported ZT values in flexible thermoelectric materials. A flexible thermoelectric device fabricated using the printed films produces a high power density of 4.1 mW/cm(2) with 60 °C temperature difference between the hot side and cold side. The highly scalable and low cost process to fabricate flexible thermoelectric materials and devices demonstrated here opens up many opportunities to transform thermoelectric energy harvesting and cooling applications.

High-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varghese, Tony; Hollar, Courtney; Richardson, Joseph

Screen printing allows for direct conversion of thermoelectric nanocrystals into flexible energy harvesters and coolers. However, obtaining flexible thermoelectric materials with high figure of merit ZT through printing is an exacting challenge due to the difficulties to synthesize high-performance thermoelectric inks and the poor density and electrical conductivity of the printed films. Here, we demonstrate high-performance flexible films and devices by screen printing bismuth telluride based nanocrystal inks synthesized using a microwave-stimulated wet-chemical method. Thermoelectric films of several tens of microns thickness were screen printed onto a flexible polyimide substrate followed by cold compaction and sintering. The n-type films demonstratemore » a peak ZT of 0.43 along with superior flexibility, which is among the highest reported ZT values in flexible thermoelectric materials. A flexible thermoelectric device fabricated using the printed films produces a high power density of 4.1 mW/cm 2 with 60°C temperature difference between the hot side and cold side. In conclusion, the highly scalable and low cost process to fabricate flexible thermoelectric materials and devices demonstrated here opens up many opportunities to transform thermoelectric energy harvesting and cooling applications.« less

High-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals

DOE PAGES

Varghese, Tony; Hollar, Courtney; Richardson, Joseph; ...

2016-09-12

Screen printing allows for direct conversion of thermoelectric nanocrystals into flexible energy harvesters and coolers. However, obtaining flexible thermoelectric materials with high figure of merit ZT through printing is an exacting challenge due to the difficulties to synthesize high-performance thermoelectric inks and the poor density and electrical conductivity of the printed films. Here, we demonstrate high-performance flexible films and devices by screen printing bismuth telluride based nanocrystal inks synthesized using a microwave-stimulated wet-chemical method. Thermoelectric films of several tens of microns thickness were screen printed onto a flexible polyimide substrate followed by cold compaction and sintering. The n-type films demonstratemore » a peak ZT of 0.43 along with superior flexibility, which is among the highest reported ZT values in flexible thermoelectric materials. A flexible thermoelectric device fabricated using the printed films produces a high power density of 4.1 mW/cm 2 with 60°C temperature difference between the hot side and cold side. In conclusion, the highly scalable and low cost process to fabricate flexible thermoelectric materials and devices demonstrated here opens up many opportunities to transform thermoelectric energy harvesting and cooling applications.« less

High-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals

PubMed Central

Varghese, Tony; Hollar, Courtney; Richardson, Joseph; Kempf, Nicholas; Han, Chao; Gamarachchi, Pasindu; Estrada, David; Mehta, Rutvik J.; Zhang, Yanliang

2016-01-01

Screen printing allows for direct conversion of thermoelectric nanocrystals into flexible energy harvesters and coolers. However, obtaining flexible thermoelectric materials with high figure of merit ZT through printing is an exacting challenge due to the difficulties to synthesize high-performance thermoelectric inks and the poor density and electrical conductivity of the printed films. Here, we demonstrate high-performance flexible films and devices by screen printing bismuth telluride based nanocrystal inks synthesized using a microwave-stimulated wet-chemical method. Thermoelectric films of several tens of microns thickness were screen printed onto a flexible polyimide substrate followed by cold compaction and sintering. The n-type films demonstrate a peak ZT of 0.43 along with superior flexibility, which is among the highest reported ZT values in flexible thermoelectric materials. A flexible thermoelectric device fabricated using the printed films produces a high power density of 4.1 mW/cm2 with 60 °C temperature difference between the hot side and cold side. The highly scalable and low cost process to fabricate flexible thermoelectric materials and devices demonstrated here opens up many opportunities to transform thermoelectric energy harvesting and cooling applications. PMID:27615036

Modifications of the IBM personal computer synchronous communications support programs for use with the Multics

USGS Publications Warehouse

Kork, John O.

1983-01-01

Version 1.00 of the Asynchronous Communications Support supplied with the IBM Personal Computer must be modified to be used for communications with Multics. Version 2.00 can be used as supplied, but error checking and screen printing capabilities can be added by using modifications very similar to those required for Version 1.00. This paper describes and lists required programs on Multics and appropriate modifications to both Versions 1.00 and 2.00 of the programs supplied by IBM.

A Water-Based Silver-Nanowire Screen-Print Ink for the Fabrication of Stretchable Conductors and Wearable Thin-Film Transistors

DOE PAGES

Liang, Jiajie; Tong, Kwing; Pei, Qibing

2016-05-09

Silver nanowire is a very promising material for fabricating compliant conductors which are essential for stretchable/wearable electronic devices. Screen printing is a cost-effective and scalable technology to fabricate large-area thin film coatings with modest pattern resolution. The biggest challenge to prepare a screen printable silver nanowire ink stems from the low viscosity of silver nanowire dispersions and that the addition of a thickening agent could dramatically increase the inter-nanowire contact resistance in the resulting coating. Herein, we report the synthesis of a water-based silver nanowire ink, which was formulated with low solid contents, high viscosity at 0.1 s -1 shearmore » rate, and appropriate rheological behavior suitable for screen printing. Silver nanowire coating patterns were screen printed with uniform sharp edges, ~50 μm resolution, and electrical conductivity as high as 4.67 × 10 4 S cm -1. The screen printed silver nanowires were then used to fabricate a composite conductor that retained a conductivity greater than 10,000 S cm -1 under 70% tensile strain. Fully printed and stretchable/wearable thin-film transistor arrays were also fabricated by employing the screen printed composite conductor as the source, drain, and gate, drop cast semiconducting carbon nanotubes as the channel, and a dielectric elastomer. The 10 × 6 thin-film transistor arrays had a fabrication yield of 91.7%, average mobility of 33.8 ± 3.7 cm 2V -1s -1, ON/OFF ratio ~1000, and remained stable during 1,000 cycles of wearing on and peeling off a glass tube with 5 mm diameter.« less

A Water-Based Silver-Nanowire Screen-Print Ink for the Fabrication of Stretchable Conductors and Wearable Thin-Film Transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Jiajie; Tong, Kwing; Pei, Qibing

Silver nanowire is a very promising material for fabricating compliant conductors which are essential for stretchable/wearable electronic devices. Screen printing is a cost-effective and scalable technology to fabricate large-area thin film coatings with modest pattern resolution. The biggest challenge to prepare a screen printable silver nanowire ink stems from the low viscosity of silver nanowire dispersions and that the addition of a thickening agent could dramatically increase the inter-nanowire contact resistance in the resulting coating. Herein, we report the synthesis of a water-based silver nanowire ink, which was formulated with low solid contents, high viscosity at 0.1 s -1 shearmore » rate, and appropriate rheological behavior suitable for screen printing. Silver nanowire coating patterns were screen printed with uniform sharp edges, ~50 μm resolution, and electrical conductivity as high as 4.67 × 10 4 S cm -1. The screen printed silver nanowires were then used to fabricate a composite conductor that retained a conductivity greater than 10,000 S cm -1 under 70% tensile strain. Fully printed and stretchable/wearable thin-film transistor arrays were also fabricated by employing the screen printed composite conductor as the source, drain, and gate, drop cast semiconducting carbon nanotubes as the channel, and a dielectric elastomer. The 10 × 6 thin-film transistor arrays had a fabrication yield of 91.7%, average mobility of 33.8 ± 3.7 cm 2V -1s -1, ON/OFF ratio ~1000, and remained stable during 1,000 cycles of wearing on and peeling off a glass tube with 5 mm diameter.« less

Characterization of screen-printed electrodes for dielectric elastomer (DE) membranes: influence of screen dimensions and electrode thickness on actuator performance

NASA Astrophysics Data System (ADS)

Fasolt, Bettina; Hodgins, Micah; Seelecke, Stefan

2016-04-01

Screen printing is used as a method for printing electrodes on silicone thin films for the fabrication of dielectric elastomer transducers (DET). This method can be used to manufacture a multitude of patternable designs for actuator and sensor applications, implementing the same method for prototyping as well as large-scale production. The fabrication of DETs does not only require the development of a flexible, highly conductive electrode material, which adheres to a stretched and unstretched silicone film, but also calls for a thorough understanding of the effects of the different printing parameters. This work studies the influence of screen dimensions (open area, mesh thickness) as well as the influence of multiple-layer- printing on the electrode stiffness, electrical resistance and capacitance as well as actuator performance. The investigation was conducted in a custom-built testing device, which enabled an electro-mechanical characterization of the DET, simultaneously measuring parameters such as strain, voltage, current, force, sheet resistance, capacitance and membrane thickness. Magnified pictures of the electrodes will additionally illustrate the effects of the different printing parameters.

Can tailored interventions increase mammography use among HMO women?

PubMed

Lipkus, I M; Rimer, B K; Halabi, S; Strigo, T S

2000-01-01

Telephone counseling and tailored print communications have emerged as promising methods for promoting mammography screening. However, there has been little research testing, within the same randomized field trial, of the efficacy of these two methods compared to a high-quality usual care system for enhancing screening. This study addressed the question: Compared to usual care, is tailored telephone counseling more effective than tailored print materials for promoting mammography screening? Three-year randomized field trial. One thousand ninety-nine women aged 50 and older recruited from a health maintenance organization in North Carolina. Women were randomized to 1 of 3 groups: (1) usual care, (2) tailored print communications, and (3) tailored telephone counseling. Adherence to mammography screening based on self-reports obtained during 1995, 1996, and 1997. Compared to usual care alone, telephone counseling promoted a significantly higher proportion of women having mammograms on schedule (71% vs 61%) than did tailored print (67% vs 61%) but only after the first year of intervention (during 1996). Furthermore, compared to usual care, telephone counseling was more effective than tailored print materials at promoting being on schedule with screening during 1996 and 1997 among women who were off-schedule during the previous year. The effects of the intervention were most pronounced after the first intervention. Compared to usual care, telephone counseling seemed particularly effective at promoting change among nonadherent women, the group for whom the intervention was developed. These results suggest that telephone counseling, rather than tailored print, might be the preferred first-line intervention for getting nonadherent women on schedule for mammography screening. Many questions would have to be answered about why the tailored print intervention was not more powerful. Nevertheless, it is clear that additional interventions will be needed to maintain women's adherence to mammography. Medical Subject Headings (MeSH): mammography screening, telephone counseling, tailored print communications, barriers.

Smartphone-based cyclic voltammetry system with graphene modified screen printed electrodes for glucose detection.

PubMed

Ji, Daizong; Liu, Lei; Li, Shuang; Chen, Chen; Lu, Yanli; Wu, Jiajia; Liu, Qingjun

2017-12-15

Smartphone-based electrochemical devices have such advantages as the low price, miniaturization, and obtaining the real-time data. As a popular electrochemical method, cyclic voltammetry (CV) has shown its great practicability for quantitative detection and electrodes modification. In this study, a smartphone-based CV system with a simple method of electrode modification was constructed to perform electrochemical detections. The system was composed of these main portions: modified electrodes, portable electrochemical detector and smartphone. Among them, the detector was comprised of an energy transformation module applying the stimuli signals, and a low-cost potentiostat module for CV measurements with a Bluetooth module for transmitting data and commands. With an Application (App), the smartphone was used as the controller and displayer of the system. Through controlling of different scan rates, the smartphone-based system could perform CV detections for redox couples with test errors less than 3.8% compared to that of commercial electrochemical workstation. Also, the reduced graphene oxide (rGO) and sensitive substance could be modified by the system on the screen printed electrodes for detections. As a demonstration, 3-amino phenylboronic acid (APBA) was used as the sensitive substance to fabricate a glucose sensor. Finally, the experimental data of the system were shown the linear, sensitive, and specific responses to glucose at different doses, even in blood serum as low as about 0.026mM with 3δ/slope calculation. Thus, the system could show great potentials of detection and modification of electrodes in various fields, such as public health, water monitoring, and food quality. Copyright © 2017 Elsevier B.V. All rights reserved.

A Disposable Organophosphorus Pesticides Enzyme Biosensor Based on Magnetic Composite Nano-Particles Modified Screen Printed Carbon Electrode

PubMed Central

Gan, Ning; Yang, Xin; Xie, Donghua; Wu, Yuanzhao; Wen, Weigang

2010-01-01

A disposable organophosphorus pesticides (OPs) enzyme biosensor based on magnetic composite nanoparticle-modified screen printed carbon electrodes (SPCE) has been developed. Firstly, an acetylcholinesterase (AChE)-coated Fe3O4/Au (GMP) magnetic nanoparticulate (GMP-AChE) was synthesized. Then, GMP-AChE was absorbed on the surface of a SPCE modified by carbon nanotubes (CNTs)/nano-ZrO2/prussian blue (PB)/Nafion (Nf) composite membrane by an external magnetic field. Thus, the biosensor (SPCE│CNTs/ZrO2/PB/Nf│GMP-AChE) for OPs was fabricated. The surface of the biosensor was characterized by scanning electron micrography (SEM) and X-ray fluorescence spectrometery (XRFS) and its electrochemical properties were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The degree of inhibition (A%) of the AChE by OPs was determined by measuring the reduction current of the PB generated by the AChE-catalyzed hydrolysis of acetylthiocholine (ATCh). In pH = 7.5 KNO3 solution, the A was related linearly to the concentration of dimethoate in the range from 1.0 × 10−3–10 ng·mL−1 with a detection limit of 5.6 × 10−4 ng·mL−1. The recovery rates in Chinese cabbage exhibited a range of 88%–105%. The results were consistent with the standard gas chromatography (GC) method. Compared with other enzyme biosensors the proposed biosensor exhibited high sensitivity, good selectivity with disposable, low consumption of sample. In particular its surface can be easily renewed by removal of the magnet. The convenient, fast and sensitive voltammetric measurement opens new opportunities for OPs analysis. PMID:22315558

Electrochemically reduced graphene oxide-modified screen-printed carbon electrodes for a simple and highly sensitive electrochemical detection of synthetic colorants in beverages.

PubMed

Jampasa, Sakda; Siangproh, Weena; Duangmal, Kiattisak; Chailapakul, Orawon

2016-11-01

A simple and highly sensitive electrochemical sensor based on an electrochemically reduced graphene oxide-modified screen-printed carbon electrode (ERGO-SPCE) for the simultaneous determination of sunset yellow (SY) and tartrazine (TZ) was proposed. An ERGO film was coated onto the electrode surface using a cyclic voltammetric method and then characterized by scanning electron microscopy (SEM). In 0.1M phosphate buffer at a pH of 6, the two oxidation peaks of SY and TZ appeared separately at 0.41 and 0.70V, respectively. Surprisingly, the electrochemical response remarkably increased approximately 90- and 20-fold for SY and TZ, respectively, using the modified electrode in comparison to the unmodified electrode. The calibration curves exhibited linear ranges from 0.01 to 20.0µM for SY and from 0.02 to 20.0µM for TZ. The limits of detection were found to be 0.50 and 4.50nM (at S/N=3) for SY and TZ, respectively. Furthermore, this detection platform provided very high selectivity for the measurement of both colorants. This electrochemical sensor was successfully applied to determine the amount of SY and TZ in commercial beverages. Comparison of the results obtained from this proposed method to those obtained by an in-house standard technique proved that this developed method has good agreement in terms of accuracy for practical applications. This sensor offers an inexpensive, rapid and sensitive determination. The proposed system is therefore suitable for routine analysis and should be an alternative method for the analysis of food colorants. Copyright © 2016 Elsevier B.V. All rights reserved.

Screen-Printing of ZnO Nanostructures from Sol-Gel Solutions for Their Application in Dye-Sensitized Solar Cells.

PubMed

Sarkar, Kuhu; Braden, Erik V; Bonke, Shannon A; Bach, Udo; Müller-Buschbaum, Peter

2015-08-24

Diblock copolymers have been used in sol-gel synthesis to successfully tailor the nanoscale morphology of thin ZnO films. As the fabrication of several-micron-thick mesoporous films such as those required in dye-sensitized solar cells (DSSCs) was difficult with this approach, we exploited the benefits of diblock-copolymer-directed synthesis that made it compatible with screen printing. The simple conversion of the diblock copolymer ZnO precursor sol to a screen-printing paste was not possible as it resulted in poor film properties. To overcome this problem, an alternative route is proposed in which the diblock copolymer ZnO precursor sol is first blade coated and calcined, then converted to a screen-printing paste. This allows the benefits of diblock-copolymer-directed particle formation to be compatible with printing methods. The morphologies of the ZnO nanostructures were studied by SEM and correlated with the current density-voltage characteristics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Implementation and Evaluation of Two Educational Strategies to Improve Screening for Eating Disorders in Pediatric Primary Care.

PubMed

Gooding, Holly C; Cheever, Elizabeth; Forman, Sara F; Hatoun, Jonathan; Jooma, Farah; Touloumtzis, Currie; Vernacchio, Louis

2017-05-01

Routine screening for disordered eating or body image concerns is recommended by the American Academy of Pediatrics. We evaluated the ability of two educational interventions to increase screening for eating disorders in pediatric primary care practice, predicting that the "active-learning" group would have an increase in documented screening after intervention. We studied 303 practitioners in a large independent practice association located in the northeastern United States. We used a quasi-experimental design to test the effect of printed educational materials ("print-learning" group, n = 280 participants) compared with in-person shared learning followed by on-line spaced education ("active-learning" group, n = 23 participants) on documented screening of adolescents for eating disorder symptoms during preventive care visits. A subset of 88 participants completed additional surveys regarding knowledge of eating disorders, comfort screening for, diagnosing, and treating eating disorders, and satisfaction with their training regarding eating disorders. During the preintervention period, 4.5% of patients seen by practitioners in both the print-learning and active-learning groups had chart documentation of screening for eating disorder symptoms or body image concerns. This increased to 22% in the active-learning group and 5.7% in the print-learning group in the postintervention period, a statistically significant result. Compared with print-learning participants, active-learning group participants had greater eating disorder knowledge scores, increases in comfort diagnosing eating disorders, and satisfaction with their training in this area. In-person shared learning followed by on-line spaced education is more effective than print educational materials for increasing provider documentation of screening for eating disorders in primary care. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Screen printing of a capacitive cantilever-based motion sensor on fabric using a novel sacrificial layer process for smart fabric applications

NASA Astrophysics Data System (ADS)

Wei, Yang; Torah, Russel; Yang, Kai; Beeby, Steve; Tudor, John

2013-07-01

Free-standing cantilevers have been fabricated by screen printing sacrificial and structural layers onto a standard polyester cotton fabric. By printing additional conductive layers, a complete capacitive motion sensor on fabric using only screen printing has been fabricated. This type of free-standing structure cannot currently be fabricated using conventional fabric manufacturing processes. In addition, compared to conventional smart fabric fabrication processes (e.g. weaving and knitting), screen printing offers the advantages of geometric design flexibility and the ability to simultaneously print multiple devices of the same or different designs. Furthermore, a range of active inks exists from the printed electronics industry which can potentially be applied to create many types of smart fabric. Four cantilevers with different lengths have been printed on fabric using a five-layer structure with a sacrificial material underneath the cantilever. The sacrificial layer is subsequently removed at 160 °C for 30 min to achieve a freestanding cantilever above the fabric. Two silver electrodes, one on top of the cantilever and the other on top of the fabric, are used to capacitively detect the movement of the cantilever. In this way, an entirely printed motion sensor is produced on a standard fabric. The motion sensor was initially tested on an electromechanical shaker rig at a low frequency range to examine the linearity and the sensitivity of each design. Then, these sensors were individually attached to a moving human forearm to evaluate more representative results. A commercial accelerometer (Microstrain G-link) was mounted alongside for comparison. The printed sensors have a similar motion response to the commercial accelerometer, demonstrating the potential of a printed smart fabric motion sensor for use in intelligent clothing applications.

Design for low-cost gas metal arc weld-based aluminum 3-D printing

NASA Astrophysics Data System (ADS)

Haselhuhn, Amberlee S.

Additive manufacturing, commonly known as 3-D printing, has the potential to change the state of manufacturing across the globe. Parts are made, or printed, layer by layer using only the materials required to form the part, resulting in much less waste than traditional manufacturing methods. Additive manufacturing has been implemented in a wide variety of industries including aerospace, medical, consumer products, and fashion, using metals, ceramics, polymers, composites, and even organic tissues. However, traditional 3-D printing technologies, particularly those used to print metals, can be prohibitively expensive for small enterprises and the average consumer. A low-cost open-source metal 3-D printer has been developed based upon gas metal arc weld (GMAW) technology. Using this technology, substrate release mechanisms have been developed, allowing the user to remove a printed metal part from a metal substrate by hand. The mechanical and microstructural properties of commercially available weld alloys were characterized and used to guide alloy development in 4000 series aluminum-silicon alloys. Wedge casting experiments were performed to screen magnesium, strontium, and titanium boride alloying additions in hypoeutectic aluminum-silicon alloys for their properties and the ease with which they could be printed. Finally, the top performing alloys, which were approximately 11.6% Si modified with strontium and titanium boride were cast, extruded, and drawn into wire. These wires were printed and the mechanical and microstructural properties were compared with those of commercially available alloys. This work resulted in an easier-to-print aluminum-silicon-strontium alloy that exhibited lower porosity, equivalent yield and tensile strengths, yet nearly twice the ductility compared to commercial alloys.

Fast and Sensitive Detection of Pb2+ in Foods Using Disposable Screen-Printed Electrode Modified by Reduced Graphene Oxide

PubMed Central

Jian, Jin-Ming; Liu, Yan-Yan; Zhang, Ye-Lei; Guo, Xi-Shan; Cai, Qiang

2013-01-01

In this study, reduced graphene oxide (rGO) was electrochemically deposited on the surface of screen-printed carbon electrodes (SPCE) to prepare a disposable sensor for fast detection of Pb2+ in foods. The SEM images showed that the rGO was homogeneously deposited onto the electrode surface with a wrinkled nanostructure, which provided 2D bridges for electron transport and a larger active area for Pb2+ adsorption. Results showed that rGO modification enhanced the activity of the electrode surface, and significantly improved the electrochemical properties of SPCE. The rGO modified SPCE (rGO-SPCE) was applied to detect Pb2+ in standard aqueous solution, showing a sharp stripping peak and a relatively constant peak potential in square wave anodic stripping voltammetry (SWASV). The linear range for Pb2+ detection was 5∼200 ppb (R2 = 0.9923) with a low detection limit of 1 ppb (S/N = 3). The interference of Cd2+ and Cu2+ at low concentrations was effectively avoided. Finally, the rGO-SPCE was used for determination of lead in real tap water, juice, preserved eggs and tea samples. Compared with results from graphite furnace atomic absorption spectroscopy (GFAAS), the results based on rGO-SPCE were both accurate and reliable, suggesting that the disposable sensor has great potential in application for fast, sensitive and low-cost detection of Pb2+ in foods. PMID:24077322

Single Frequency Impedance Analysis on Reduced Graphene Oxide Screen-Printed Electrode for Biomolecular Detection.

PubMed

Rajesh; Singal, Shobhita; Kotnala, Ravinder K

2017-10-01

A biofunctionalized reduced graphene oxide (rGO)-modified screen-printed carbon electrode (SPCE) was constructed as an immunosensor for C-reactive protein (CRP) detection, a biomarker released in early stage acute myocardial infarction. A different approach of single frequency analysis (SFA) study was utilized for the biomolecular sensing, by monitoring the response in phase angle changes obtained at an optimized frequency resulting from antigen-antibody interactions. A set of measurements were carried out to optimize a frequency where a maximum change in phase angle was observed, and in this case, we found it at around 10 Hz. The bioelectrode was characterized by contact angle measurements, scanning electron microscopy, and electrochemical techniques. A concentration-dependent response of immunosensor to CRP with the change in phase angle, at a fixed frequency of 10 Hz, was found to be in the range of 10 ng mL -1 to 10 μg mL -1 in PBS and was fit quantitative well with the Hill-Langmuir equation. Based on the concentration-response data, the dissociation constant (K d ) was found to be 3.5 nM (with a Hill coefficient n = 0.57), which indicated a negative cooperativity with high anti-CRP (antibody)-CRP (antigen) binding at the electrode surface. A low-frequency analysis of sensing with an ease of measurement on a disposable electroactive rGO-modified electrode with high selectivity and sensitivity makes it a potential tool for biological sensors.

Sensitive HIV-1 detection in a homogeneous solution based on an electrochemical molecular beacon coupled with a nafion-graphene composite film modified screen-printed carbon electrode.

PubMed

Li, Bo; Li, Zhengliang; Situ, Bo; Dai, Zong; Liu, Qinlan; Wang, Qian; Gu, Dayong; Zheng, Lei

2014-02-15

A novel electrochemical sensing assay for sensitive determination of HIV-1 in a homogeneous solution has been developed using an electrochemical molecular beacon combined with a nafion-graphene composite film modified screen-printed carbon electrode (nafion-graphene/SPCE). The electrochemical molecular beacon (CAs-MB), comprising a special recognition sequence for the conserved region of the HIV-1 gag gene and a pair of carminic acid molecules as a marker, can indicate the presence of the HIV-1 target by its on/off electrochemical signal behavior. It is suitable for direct, electrochemical determination of HIV-1, thereby simplifying the detection procedure and improving the signal-to-noise (S/N) ratio. To further improve the sensitivity, the nafion-graphene/SPCE was used to monitor changes in the CAs-MB, which has notable advantages, such as being ultrasensitive, inexpensive, and disposable. Under optimized conditions, the peak currents showed a linear relationship with the logarithm of target oligonucleotide concentrations ranging from 40 nM to 2.56 μM, with a detection limit of 5 nM (S/N=3). This sensing assay also displays a good stability, with a recovery of 88-106.8% and RSD<7% (n=5) in real serum samples. This work may lead to the development of an effective method for early point-of-care diagnosis of HIV-1 infection. © 2013 Elsevier B.V. All rights reserved.

A screen-printed flexible flow sensor

NASA Astrophysics Data System (ADS)

Moschos, A.; Syrovy, T.; Syrova, L.; Kaltsas, G.

2017-04-01

A thermal flow sensor was printed on a flexible plastic substrate using exclusively screen-printing techniques. The presented device was implemented with custom made screen-printed thermistors, which allows simple, cost-efficient production on a variety of flexible substrates while maintaining the typical advantages of thermal flow sensors. Evaluation was performed for both static (zero flow) and dynamic conditions using a combination of electrical measurements and IR imaging techniques in order to determine important characteristics, such as temperature response, output repeatability, etc. The flow sensor was characterized utilizing the hot-wire and calorimetric principles of operation, while the preliminary results appear to be very promising, since the sensor was successfully evaluated and displayed adequate sensitivity in a relatively wide flow range.

Screen-printed nanoparticles as anti-counterfeiting tags

NASA Astrophysics Data System (ADS)

Campos-Cuerva, Carlos; Zieba, Maciej; Sebastian, Victor; Martínez, Gema; Sese, Javier; Irusta, Silvia; Contamina, Vicente; Arruebo, Manuel; Santamaria, Jesus

2016-03-01

Metallic nanoparticles with different physical properties have been screen printed as authentication tags on different types of paper. Gold and silver nanoparticles show unique optical signatures, including sharp emission bandwidths and long lifetimes of the printed label, even under accelerated weathering conditions. Magnetic nanoparticles show distinct physical signals that depend on the size of the nanoparticle itself. They were also screen printed on different substrates and their magnetic signals read out using a magnetic pattern recognition sensor and a vibrating sample magnetometer. The novelty of our work lies in the demonstration that the combination of nanomaterials with optical and magnetic properties on the same printed support is possible, and the resulting combined signals can be used to obtain a user-configurable label, providing a high degree of security in anti-counterfeiting applications using simple commercially-available sensors.

Screen-printed nanoparticles as anti-counterfeiting tags.

PubMed

Campos-Cuerva, Carlos; Zieba, Maciej; Sebastian, Victor; Martínez, Gema; Sese, Javier; Irusta, Silvia; Contamina, Vicente; Arruebo, Manuel; Santamaria, Jesus

2016-03-04

Metallic nanoparticles with different physical properties have been screen printed as authentication tags on different types of paper. Gold and silver nanoparticles show unique optical signatures, including sharp emission bandwidths and long lifetimes of the printed label, even under accelerated weathering conditions. Magnetic nanoparticles show distinct physical signals that depend on the size of the nanoparticle itself. They were also screen printed on different substrates and their magnetic signals read out using a magnetic pattern recognition sensor and a vibrating sample magnetometer. The novelty of our work lies in the demonstration that the combination of nanomaterials with optical and magnetic properties on the same printed support is possible, and the resulting combined signals can be used to obtain a user-configurable label, providing a high degree of security in anti-counterfeiting applications using simple commercially-available sensors.

76 FR 23791 - Laminated Woven Sacks From the People's Republic of China: Initiation of Anti-Circumvention Inquiry

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-28

... whether laminated woven sacks printed with two colors in register and with the use of a screening process... two ink colors printed in register and a screening process \\1\\ which allows for one of the original inks to print on the sacks in a different shade than the original ink color. Specifically, Petitioners...

The challenge of screen printed Ag metallization on nano-scale poly-silicon passivated contacts for silicon solar cells

NASA Astrophysics Data System (ADS)

Jiang, Lin; Song, Lixin; Yan, Li; Becht, Gregory; Zhang, Yi; Hoerteis, Matthias

2017-08-01

Passivated contacts can be used to reduce metal-induced recombination for higher energy conversion efficiency for silicon solar cells, and are obtained increasing attentions by PV industries in recent years. The reported thicknesses of passivated contact layers are mostly within tens of nanometer range, and the corresponding metallization methods are realized mainly by plating/evaporation technology. This high cost metallization cannot compete with the screen printing technology, and may affect its market potential comparing with the presently dominant solar cell technology. Very few works have been reported on screen printing metallization on passivated contact solar cells. Hence, there is a rising demand to realize screen printing metallization technology on this topic. In this work, we investigate applying screen printing metallization pastes on poly-silicon passivated contacts. The critical challenge for us is to build low contact resistance that can be competitive to standard technology while restricting the paste penetrations within the thin nano-scale passivated contact layers. The contact resistivity of 1.1mohm-cm2 and the open circuit voltages > 660mV are achieved, and the most appropriate thickness range is estimated to be around 80 150nm.

Screen printed UHF antennas on flexible substrates

NASA Astrophysics Data System (ADS)

Janeczek, Kamil; Młożniak, Anna; Kozioł, Grażyna; Araźna, Aneta; Jakubowska, Małgorzata; Bajurko, Paweł

2010-09-01

Printed electronics belongs to the most important developing electronics technologies. It provides new possibilities to produce low cost and large area devices. In its range several applications can be distinguished like printed batteries, OLED, biosensors, photovoltaic cells or RFID tags. In the presented investigation, antennas working in UHF frequency range were elaborated. It can be applied in the future for flexible RFID tags. To produce these antennas polymer paste with silver flakes was used. It was deposited on two flexible substrates (foil and photo paper) with screen printing techniques. After printing process surface profile, electrical and microwave parameters of performed antennas were measured using digital multimeter and network analyzer, relatively. Furthermore, a thickness of printed layers was measured.

Amperometric immunoassay for the obesity biomarker amylin using a screen printed carbon electrode functionalized with an electropolymerized carboxylated polypyrrole.

PubMed

Martínez-García, Gonzalo; Sánchez-Tirado, Esther; González-Cortés, Araceli; Yáñez-Sedeño, Paloma; Pingarrón, José M

2018-06-09

Amylin (the islet amyloid polypeptide) is a hormone related to adiposity, hunger and satiety. It is co-secreted with insulin from pancreatic B-cells. An amperometric immunosensor is presented here for the determination of amylin. It is making use of a screen printed carbon electrode (SPCE) functionalized with electropolymerized poly(pyrrole propionic acid) (pPPA) with abundant carboxyl groups that facilitate covalent binding of antibody against amylin. A competitive immunoassay was implemented using biotinylated amylin and streptavidin labeled with horse radish peroxidase (HRP-Strept) as the enzymatic tracer. The amperometric detection of H 2 O 2 mediated by hydroquinone was employed as an electrochemical probe to monitor the affinity reaction. The variables involved in the preparation and function of the immunosensor were optimized and the electrodes were characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The calibration graph for amylin, obtained by amperometry at -200 mV vs Ag pseudo-reference electrode, showed a range of linearity extending from 1.0 fg∙mL -1 to 50 pg∙mL -1 , with a detection limit of 0.92 fg∙mL -1 . This is approximately 7000 times lower than the minimum detectable concentration reported for the ELISA immunoassays available for amylin. The assay has excellent reproducibility and good selectivity over potential interferents. Graphical abstract Schematic of an amperometric competitive immunoassay for the obesity biomarker amylin using a poly(pyrrole propionic acid)-modified screen-printed electrode. The detection limit is 0.92 fg∙mL-1 amylin. The method provides excellent reproducibility for the measurements, good selectivity and successful applicability to human urine and serum samples.

Recent Advances in the Fabrication and Application of Screen-Printed Electrochemical (Bio)Sensors Based on Carbon Materials for Biomedical, Agri-Food and Environmental Analyses

PubMed Central

Hughes, Gareth; Westmacott, Kelly; Honeychurch, Kevin C.; Crew, Adrian; Pemberton, Roy M.; Hart, John P.

2016-01-01

This review describes recent advances in the fabrication of electrochemical (bio)sensors based on screen-printing technology involving carbon materials and their application in biomedical, agri-food and environmental analyses. It will focus on the various strategies employed in the fabrication of screen-printed (bio)sensors, together with their performance characteristics; the application of these devices for the measurement of selected naturally occurring biomolecules, environmental pollutants and toxins will be discussed. PMID:27690118

Impact electrochemistry on screen-printed electrodes for the detection of monodispersed silver nanoparticles of sizes 10-107 nm.

PubMed

Nasir, Muhammad Zafir Mohamad; Pumera, Martin

2016-10-12

Impact electrochemistry provides a useful alternative technique for the detection of silver nanoparticles in solutions. The combined use of impact electrochemistry on screen-printed electrodes (SPEs) for the successful detection of silver nanoparticles provides an avenue for future on-site, point-of-care detection devices to be made for environmental, medicinal and biological uses. Here we discuss the use of screen-printed electrodes for the detection of well-defined monodispersed silver nanoparticles of sizes 10, 20, 40, 80, and 107 nm.

Spatial Control of Bacteria Using Screen Printing

PubMed Central

Moon, Soonhee; Fritz, Ian L.; Singer, Zakary S.

2016-01-01

Abstract Synthetic biology has led to advances in both our understanding and engineering of genetic circuits that affect spatial and temporal behaviors in living cells. A growing array of native and synthetic circuits such as oscillators, pattern generators, and cell–cell communication systems has been studied, which exhibit spatiotemporal properties. To better understand the design principles of these genetic circuits, there is a need for versatile and precise methods for patterning cell populations in various configurations. In this study, we develop a screen printing methodology to pattern bacteria on agar, glass, and paper surfaces. Initially, we tested three biocompatible resuspension media with appropriate rheological properties for screen printing. Using microscopy, we characterized the resolution and bleed of bacteria screen prints on agar and glass surfaces, obtaining resolutions as low as 188 μm. Next, we engineered bacterial strains producing visible chromoproteins analogous to the cyan, magenta, and yellow subtractive color system for the creation of multicolored bacteria images. Using this system, we printed distinct populations in overlapping or interlocking designs on both paper and agar substrates. These proof-of-principle experiments demonstrated how the screen printing method could be used to study microbial community interactions and pattern formation of biofilms at submillimeter length scales. Overall, our approach allows for rapid and precise prototyping of patterned bacteria species that will be useful in the understanding and engineering of spatiotemporal behaviors in microbial communities. PMID:29577061

High-Performance Screen-Printed Thermoelectric Films on Fabrics.

PubMed

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook; Ko, Dong-Su; Kim, Hyun-Sik; Kim, Sang Il; Yin, Lu; Schlossberg, Sarah M; Cui, Shuang; You, Jung-Min; Kwon, Soonshin; Zheng, Jianlin; Wang, Joseph; Chen, Renkun

2017-08-04

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screen-printing of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5 Sb 1.5 Te 3 or n-type Bi 2 Te 2.7 Se 0.3 ), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscosity for printability at a very small concentration (0.45-0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.

Screen printing as a scalable and low-cost approach for rigid and flexible thin-film transistors using separated carbon nanotubes.

PubMed

Cao, Xuan; Chen, Haitian; Gu, Xiaofei; Liu, Bilu; Wang, Wenli; Cao, Yu; Wu, Fanqi; Zhou, Chongwu

2014-12-23

Semiconducting single-wall carbon nanotubes are very promising materials in printed electronics due to their excellent mechanical and electrical property, outstanding printability, and great potential for flexible electronics. Nonetheless, developing scalable and low-cost approaches for manufacturing fully printed high-performance single-wall carbon nanotube thin-film transistors remains a major challenge. Here we report that screen printing, which is a simple, scalable, and cost-effective technique, can be used to produce both rigid and flexible thin-film transistors using separated single-wall carbon nanotubes. Our fully printed top-gated nanotube thin-film transistors on rigid and flexible substrates exhibit decent performance, with mobility up to 7.67 cm2 V(-1) s(-1), on/off ratio of 10(4)∼10(5), minimal hysteresis, and low operation voltage (<10 V). In addition, outstanding mechanical flexibility of printed nanotube thin-film transistors (bent with radius of curvature down to 3 mm) and driving capability for organic light-emitting diode have been demonstrated. Given the high performance of the fully screen-printed single-wall carbon nanotube thin-film transistors, we believe screen printing stands as a low-cost, scalable, and reliable approach to manufacture high-performance nanotube thin-film transistors for application in display electronics. Moreover, this technique may be used to fabricate thin-film transistors based on other materials for large-area flexible macroelectronics, and low-cost display electronics.

Humidity Sensors Printed on Recycled Paper and Cardboard

PubMed Central

Mraović, Matija; Muck, Tadeja; Pivar, Matej; Trontelj, Janez; Pleteršek, Anton

2014-01-01

Research, design, fabrication and results of various screen printed capacitive humidity sensors is presented in this paper. Two types of capacitive humidity sensors have been designed and fabricated via screen printing on recycled paper and cardboard, obtained from the regional paper and cardboard industry. As printing ink, commercially available silver nanoparticle-based conductive ink was used. A considerable amount of work has been devoted to the humidity measurement methods using paper as a dielectric material. Performances of different structures have been tested in a humidity chamber. Relative humidity in the chamber was varied in the range of 35%–80% relative humidity (RH) at a constant temperature of 23 °C. Parameters of interest were capacitance and conductance of each sensor material, as well as long term behaviour. Process reversibility has also been considered. The results obtained show a mainly logarithmic response of the paper sensors, with the only exception being cardboard-based sensors. Recycled paper-based sensors exhibit a change in value of three orders of magnitude, whereas cardboard-based sensors have a change in value of few 10s over the entire scope of relative humidity range (RH 35%–90%). Two different types of capacitor sensors have been investigated: lateral (comb) type sensors and modified, perforated flat plate type sensors. The objective of the present work was to identify the most important factors affecting the material performances with humidity, and to contribute to the development of a sensor system supported with a Radio Frequency Identification (RFID) chip directly on the material, for use in smart packaging applications. Therefore, the authors built a passive and a battery-supported wireless module based on SL900A smart sensory tag's IC to achieve UHF-RFID functionality with data logging capability. PMID:25072347

Preparation of a YAG:Ce phosphor glass by screen-printing technology and its application in LED packaging.

PubMed

Yang, Liang; Chen, Mingxiang; Lv, Zhicheng; Wang, Simin; Liu, Xiaogang; Liu, Sheng

2013-07-01

A simple and practical method for preparing phosphor glass is proposed. Phosphor distribution and element analysis are investigated by optical microscope and field emission scanning electron microscope (FE-SEM). The phosphor particles dispersed in the matrix are vividly observed, and their distributions are uniform. Spectrum distribution and color coordinates dependent on the thickness of the screen-printed phosphor layer coupled with a blue light emitting diode (LED) chip are studied. The luminous efficacy of the 75 μm printed phosphor-layer phosphor glass packaged white LED is 81.24 lm/W at 350 mA. This study opens up many possibilities for applications using the phosphor glass on a selected chip in which emission is well absorbed by all phosphors. The screen-printing technique also offers possibilities for the design and engineering of complex phosphor layers on glass substrates. Phosphor screen-printing technology allows the realization of high stability and thermal conductivity for the phosphor layer. This phosphor glass method provides many possibilities for LED packing, including thin-film flip chip and remote phosphor technology.

SCREEN-PRINTED TYROSINASE-CONTAINING ELECTRODES FOR THE BIOSENSING OF ENZYME INHIBITORS

EPA Science Inventory

Disposal amperometric inhibition biosensors have been microfabricated by screen printing a tyrosinase-containing carbon ink. The decrease in the substrate (catechol) steady-state current, caused by the addition of various pesticides and herbicides, offers convenient quantitation ...

Fabrication of a wettability-gradient surface on copper by screen-printing techniques

NASA Astrophysics Data System (ADS)

Huang, Ding-Jun; Leu, Tzong-Shyng

2015-08-01

In this study, a screen-printing technique is utilized to fabricate a wettability-gradient surface on a copper substrate. The pattern definitions on the copper surface were freely fabricated to define the regions with different wettabilities, for which the printing definition technique was developed as an alternative to the existing costly photolithography techniques. This fabrication process using screen printing in tandem with chemical modification methods can easily realize an excellent wettability-gradient surface with superhydrophobicity and superhydrophilicity. Surface analyses were performed to characterize conditions in some fabrication steps. A water droplet movement sequence is provided to clearly demonstrate the droplet-driving effectiveness of the fabricated gradient surface. The droplet-driving efficiency offers a promising solution for condensation heat transfer applications in the foreseeable future.

Screen printed, transparent, and flexible electrodes based on graphene nanoplatelet pastes

NASA Astrophysics Data System (ADS)

Wróblewski, Grzegorz; Janczak, Daniel

Transparent, flexible and conducting graphene films were produced by screen printing method using printing pastes based on graphene nanoplatelets in polymer matrix. The transparency of received layers and the mechanical resistivity in several bending cycles were measured. Subsequently percolation threshold was investigated. Graphene layers were printed on diverse substrates (glass, Al2O3, PET) and afterwards for samples printed on glass different firing atmospheres (N2, H2, air) were studied. Best firing results (resistance decrease) were obtained for treatment in 250 °C in atmosphere of air. Finally investigation results were used to produce a transparent and elastic electrode for an electroluminescent display, showing the application potential of our graphene nanocomposite pastes.

A new microplatform based on titanium dioxide nanofibers/graphene oxide nanosheets nanocomposite modified screen printed carbon electrode for electrochemical determination of adenine in the presence of guanine.

PubMed

Arvand, Majid; Ghodsi, Navid; Zanjanchi, Mohammad Ali

2016-03-15

The current techniques for determining adenine have several shortcomings such as high cost, high time consumption, tedious pretreatment steps and the requirements for highly skilled personnel often restrict their use in routine analytical practice. This paper describes the development and utilization of a new nanocomposite consisting of titanium dioxide nanofibers (TNFs) and graphene oxide nanosheets (GONs) for screen printed carbon electrode (SPCE) modification. The synthesized GONs and TNFs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The modified electrode (TNFs/GONs/SPCE) was used for electrochemical characterization of adenine. The TNFs/GONs/SPCE exhibited an increase in peak current and the electron transfer kinetics and decrease in the overpotential for the oxidation reaction of adenine. Using differential pulse voltammetry (DPV), the prepared sensor showed good sensitivity for determining adenine in two ranges from 0.1-1 and 1-10 μM, with a detection limit (DL) of 1.71 nM. Electrochemical studies suggested that the TNFs/GONs/SPCE provided a synergistic augmentation on the voltammetric behavior of electrochemical oxidation of adenine, which was indicated by the improvement of anodic peak current and a decrease in anodic peak potential. The amount of adenine in pBudCE4.1 plasmid was determined via the proposed sensor and the result was in good compatibility with the sequence data of pBudCE4.1 plasmid. Copyright © 2015 Elsevier B.V. All rights reserved.

Glucose sensing on graphite screen-printed electrode modified by sparking of copper nickel alloys.

PubMed

Riman, Daniel; Spyrou, Konstantinos; Karantzalis, Alexandros E; Hrbac, Jan; Prodromidis, Mamas I

2017-04-01

Electric spark discharge was employed as a green, fast and extremely facile method to modify disposable graphite screen-printed electrodes (SPEs) with copper, nickel and mixed copper/nickel nanoparticles (NPs) in order to be used as nonenzymatic glucose sensors. Direct SPEs-to-metal (copper, nickel or copper/nickel alloys with 25/75, 50/50 and 75/25wt% compositions) sparking at 1.2kV was conducted in the absence of any solutions under ambient conditions. Morphological characterization of the sparked surfaces was performed by scanning electron microscopy, while the chemical composition of the sparked NPs was evaluated with energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The performance of the various sparked SPEs towards the electro oxidation of glucose in alkaline media and the critical role of hydroxyl ions were evaluated with cyclic voltammetry and kinetic studies. Results indicated a mixed charge transfer- and hyroxyl ion transport-limited process. Best performing sensors fabricated by Cu/Ni 50/50wt% alloy showed linear response over the concentration range 2-400μM glucose and they were successfully applied to the amperometric determination of glucose in blood. The detection limit (S/N 3) and the relative standard deviation of the method were 0.6µM and <6% (n=5, 2µM glucose), respectively. Newly devised sparked Cu/Ni graphite SPEs enable glucose sensing with distinct advantages over existing glucose chemical sensors in terms of cost, fabrication simplicity, disposability, and adaptation of green methods in sensor's development. Copyright © 2017 Elsevier B.V. All rights reserved.

Carbon nanotubes and graphene modified screen-printed carbon electrodes as sensitive sensors for the determination of phytochelatins in plants using liquid chromatography with amperometric detection.

PubMed

Dago, Àngela; Navarro, Javier; Ariño, Cristina; Díaz-Cruz, José Manuel; Esteban, Miquel

2015-08-28

Nanomaterials are of great interest for the development of electrochemical sensors. Multi-walled carbon nanotubes and graphene were used to modify the working electrode surface of different screen-printed carbon electrodes (SPCE) with the aim of improving the sensitivity of the SPCE and comparing it with the conventional glassy carbon electrode. To assay the usability of these sensors, a HPLC methodology with amperometric detection was developed to analyze several phytochelatins in plants of Hordeum vulgare and Glycine max treated with Hg(II) or Cd(II) giving detection limits in the low μmolL(-1) range. Phytochelatins are low molecular weight peptides with the general structure γ-(Glu-Cys)n-Gly (n=2-5) which are synthesized in plants in the presence of heavy metal ions. These compounds can chelate heavy metal ions by the formation of complexes which, are transported to the vacuoles, where the toxicity is not threatening. For this reason phytochelatins are essential in the detoxification of heavy metal ions in plants. The developed HPLC method uses a mobile phase of 1% of formic acid in water with KNO3 or NaCl (pH=2.00) and 1% of formic acid in acetonitrile. Electrochemical detection at different carbon-based electrodes was used. Among the sensors tested, the conventional glassy carbon electrode offers the best sensitivity although modification improves the sensitivity of the SPCE. Glutathione and several isoforms of phytochelatin two were found in plant extracts of both studied species. Copyright © 2015 Elsevier B.V. All rights reserved.

Screen-printed immunosensor modified with carbon nanotubes in a continuous-flow system for the Botrytis cinerea determination in apple tissues.

PubMed

Fernández-Baldo, Martín A; Messina, Germán A; Sanz, Maria I; Raba, Julio

2009-08-15

Botrytis cinerea is a plant-pathogenic fungus that produces the disease known as grey mould in a wide variety of agriculturally important hosts in many countries. This paper describes the development of an immunosensor coupled to carbon-based screen-printed electrodes (SPCE) modified with multi-walled carbon nanotubes (CNTs), which show a rapid and sensitive determination of B. cinerea in apple tissues (Red-delicious) using a competitive immunoassay method. Both the infected plant tissue sample and the B. cinerea-specific monoclonal antibody are allowed to react immunologically with the B. cinerea purified antigens immobilized on a rotating disk. Then, the bound antibodies are quantified by a horseradish peroxidise (HRP) enzyme labeled second antibodies specific to mouse IgG, using 4-tertbutylcatechol (4-TBC) as enzymatic mediators. The HRP, in the presence of hydrogen peroxide, catalyses the oxidation of 4-TBC to 4-tertbutyl o-benzoquinone. The electrochemical reduction back to 4-TBC is detected on SPCE-CNT at -0.15 V. The response current is inversely proportional to the amount of the B. cinerea antigens present in the fruit sample. The time consumed per assay was 30 min and the calculated detection limits for electrochemical method and the ELISA procedure are 0.02 and 10 microg mL(-1), respectively. Moreover the intra- and inter-assay coefficients of variation were below 7%. This electrochemical immunosensor promises to be usefully suited to the detection and quantification of B. cinerea in apparently healthy plant prior to the development of the symptoms.

Iridium Oxide-reduced Graphene Oxide Nanohybrid Thin Film Modified Screen-printed Electrodes as Disposable Electrochemical Paper Microfluidic pH Sensors.

PubMed

Yang, Jiang; Kwak, Tae-Joon; Zhang, Xiaodong; McClain, Robert; Chang, Woo-Jin; Gunasekaran, Sundaram

2016-11-22

A facile, controllable, inexpensive and green electrochemical synthesis of IrO2-graphene nanohybrid thin films is developed to fabricate an easy-to-use integrated paper microfluidic electrochemical pH sensor for resource-limited settings. Taking advantages from both pH meters and strips, the pH sensing platform is composed of hydrophobic barrier-patterned paper micropad (µPAD) using polydimethylsiloxane (PDMS), screen-printed electrode (SPE) modified with IrO2-graphene films and molded acrylonitrile butadiene styrene (ABS) plastic holder. Repetitive cathodic potential cycling was employed for graphene oxide (GO) reduction which can completely remove electrochemically unstable oxygenated groups and generate a 2D defect-free homogeneous graphene thin film with excellent stability and electronic properties. A uniform and smooth IrO2 film in nanoscale grain size is anodically electrodeposited onto the graphene film, without any observable cracks. The resulting IrO2-RGO electrode showed slightly super-Nernstian responses from pH 2-12 in Britton-Robinson (B-R) buffers with good linearity, small hysteresis, low response time and reproducibility in different buffers, as well as low sensitivities to different interfering ionic species and dissolved oxygen. A simple portable digital pH meter is fabricated, whose signal is measured with a multimeter, using high input-impedance operational amplifier and consumer batteries. The pH values measured with the portable electrochemical paper-microfluidic pH sensors were consistent with those measured using a commercial laboratory pH meter with a glass electrode.

Direct laser immobilization of photosynthetic material on screen printed electrodes for amperometric biosensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boutopoulos, Christos; Zergioti, Ioanna; Touloupakis, Eleftherios

This letter demonstrates the direct laser printing of photosynthetic material onto low cost nonfunctionalized screen printed electrodes for the fabrication of photosynthesis-based amperometric biosensors. The high kinetic energy of the transferred material induces direct immobilization of the thylakoids onto the electrodes without the use of linkers. This type of immobilization is able to establish efficient electrochemical contact between proteins and electrode, stabilizing the photosynthetic biomolecule and transporting electrons to the solid state device with high efficiency. The functionality of the laser printed biosensors was evaluated by the detection of a common herbicide such as Linuron.

ELECTROCHEMICAL TECHNIQUE FOR TNT USING DISPOSABLE SCREEN-PRINTED ELECTRODE

EPA Science Inventory

Screen-printed thick film electrodes are demonstrated as voltammetric sensors for measurement of 2,4,6-trinitrotoluene (TNT). The square wave voltammetric (SWV) scan technique is used to measure TNT in as little as 50 uL sample volumes. This electrochemical assay is coupled ...

A randomized comparison of print and web communication on colorectal cancer screening.

PubMed

Weinberg, David S; Keenan, Eileen; Ruth, Karen; Devarajan, Karthik; Rodoletz, Michelle; Bieber, Eric J

2013-01-28

New methods to enhance colorectal cancer (CRC) screening rates are needed. The web offers novel possibilities to educate patients and to improve health behaviors, such as cancer screening. Evidence supports the efficacy of health communications that are targeted and tailored to improve the uptake of recommendations. We identified unscreened women at average risk for CRC from the scheduling databases of obstetrics and gynecology practices in 2 large health care systems. Participants consented to a randomized controlled trial that compared CRC screening uptake after receipt of CRC screening information delivered via the web or in print form. Participants could also be assigned to a control (usual care) group. Women in the interventional arms received tailored information in a high- or low-monitoring Cognitive Social Information Processing model-defined attentional style. The primary outcome was CRC screening participation at 4 months. A total of 904 women were randomized to the interventional or control group. At 4 months, CRC screening uptake was not significantly different in the web (12.2%), print (12.0%), or control (12.9%) group. Attentional style had no effect on screening uptake for any group. Some baseline participant factors were associated with greater screening, including higher income (P = .03), stage of change (P < .001), and physician recommendation to screen (P < .001). A web-based educational intervention was no more effective than a print-based one or control (no educational intervention) in increasing CRC screening rates in women at average risk of CRC. Risk messages tailored to attentional style had no effect on screening uptake. In average-risk populations, use of the Internet for health communication without additional enhancement is unlikely to improve screening participation. clinicaltrials.gov Identifier: NCT00459030.

A gas-sensing array produced from screen-printed, zeolite-modified chromium titanate

NASA Astrophysics Data System (ADS)

Pugh, David C.; Hailes, Stephen M. V.; Parkin, Ivan P.

2015-08-01

Metal oxide semiconducting (MOS) gas sensors represent a cheap, robust and sensitive technology for detecting volatile organic compounds. MOS sensors have consistently been shown to lack sensitivity to a broad range on analytes, leading to false positive errors. In this study an array of five chromium titanate (CTO) thick-film sensors were produced. These were modified by incorporating a range of zeolites, namely β, Y, mordenite and ZSM5, into the bulk sensor material. Sensors were exposed to three common reducing gases, namely acetone, ethanol and toluene, and a machine learning technique was applied to differentiate between the different gases. All sensors produced strong resistive responses (increases in resistance) and a support vector machine (SVM) was able to classify the data to a high degree of selectivity.

EVALUATION OF BARRIERS TO THE USE OF RADIATION-CURED COATINGS IN SCREEN PRINTING

EPA Science Inventory

The report gives results of an evaluation of barriers to the use of radiation-cured coatings in screen printing. In support of the Source Reduction Review Project (SRRP), maximum achievable control technology (MACT) standards development, and the Pollution Prevention Act, EPA is ...

Metal Electrodeposition on an Integrated, Screen-Printed Electrode Assembly

ERIC Educational Resources Information Center

Chyan, Yieu; Chyan, Oliver

2008-01-01

In this lab experiment, screen-printed electrode strips are used to illustrate the essential concepts of electrochemistry, giving students an opportunity to explore metal electrodeposition processes. In the past, metal electrodeposition experiments were seldom included in general chemistry labs because of the difficulty of maintaining separate…

Low-Cost, Disposable, Flexible and Highly Reproducible Screen Printed SERS Substrates for the Detection of Various Chemicals

PubMed Central

Wu, Wei; Liu, Li; Dai, Zhigao; Liu, Juhua; Yang, Shuanglei; Zhou, Li; Xiao, Xiangheng; Jiang, Changzhong; Roy, Vellaisamy A.L.

2015-01-01

Ideal SERS substrates for sensing applications should exhibit strong signal enhancement, generate a reproducible and uniform response, and should be able to fabricate in large-scale and low-cost. Herein, we demonstrate low-cost, highly sensitive, disposable and reproducible SERS substrates by means of screen printing Ag nanoparticles (NPs) on a plastic PET (Polyethylene terephthalate) substrates. While there are many complex methods for the fabrication of SERS substrates, screen printing is suitable for large-area fabrication and overcomes the uneven radial distribution. Using as-printed Ag substrates as the SERS platform, detection of various commonly known chemicals have been done. The SERS detection limit of Rhodamine 6G (R6G) is higher than the concentration of 1 × 10−10 M. The relative standard deviation (RSD) value for 784 points on the detection of R6G and Malachite green (MG) is less than 20% revealing a homogeneous SERS distribution and high reproducibility. Moreover, melamine (MA) is detected in fresh liquid-milk without additional pretreatment, which may accelerate the application of rapid on-line detection of MA in liquid milk. Our screen printing method highlights the use of large-scale printing strategies for the fabrication of well-defined functional nanostructures with applications well beyond the field of SERS sensing. PMID:25974125

Printing and Related Support Activities Sector (NAICS 323)

EPA Pesticide Factsheets

Find environmental regulatory and compliance information for the printing sector, including NESHAPs for paper surface coating, RCRA hazardous waste guide for small business, and a pollution prevention guidance for lithographic and screen printing

Pocket Pal: A Graphic Arts Digest for Printers and Advertising Production Managers. Tenth Edition.

ERIC Educational Resources Information Center

1970

In this digest of information about printing a brief survey of the history of printing precedes detailed explanations of the processes and the materials involved in printing. The four major printing processes--letterpress, gravure, offset lithography, and screen--are explained. Steps in preparing art and copy for printing, including selection of…

The influence of the accelerated ageing on the black screen element of the Electroink prints

NASA Astrophysics Data System (ADS)

Majnaric, I.; Bolanca, Z.; Bolanca Mirkovic, I.

2010-06-01

Printing material and prints undergo changes during ageing which can be recognized in deterioration in the physical, chemical and optical properties. The aim of this work is to determine the optical changes of the prints caused by ageing of the printing material and of the prints obtained by the application of the indirect electrophotography. The change of the screen elements in lighter halftone areas, which was obtained by the usage of the microscopic image analysis, has been discussed in the article. For the preparation of samples the following papers were used: fine art paper, recycled paper and offset paper as well as black Electroink. Three sample series were observed: prints on nonaged paper and ElectroInk, prints on aged paper and ElectroInk and prints on aged paper and nonaged ElectroInk. The investigation results show that by ageing of the uncoated printing substrates the decrease of the dots on prints can be expected, while the printing on the aged paper results in the increased reproduction of the halftone dots. The obtained results are the contribution to the explanation of the influence of the accelerated ageing process of papers which are used for printing and the aged prints on the halftone dot changes. Except the mentioned determined scientific contribution the results are applicable in the area of the printing product quality as well as in the forensic science.

Development of a molecularly imprinted polymer tailored on disposable screen-printed electrodes for dual detection of EGFR and VEGF using nano-liposomal amplification strategy.

PubMed

Johari-Ahar, Mohammad; Karami, Pari; Ghanei, Mostafa; Afkhami, Abbas; Bagheri, Hasan

2018-06-01

This work demonstrates the development of a gold screen-printed electrode (Au-SPE)-based biosensor modified with a molecularly imprinted polymer and amplified using antibody-conjugated nano-liposomes. The developed biosensor was utilized for dual determination of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) as cancer biomarkers. To prepare this biosensor, Au-SPE was modified with 3,3'-dithiodipropionic acid di(N-hydroxysuccinimide ester) via self-assembly method and then the target proteins (EGFR and VEGF) were covalently attached to the modified SPE. To synthesize the molecularly imprinted polymer, monomers of acrylamide and N,N'-methylenebis(acrylamide) were polymerized around the EGFR and VEGF templates, and to characterize the prepared biosensor, electrochemical impedance spectroscopy was used for analyses of surface changes in the engineered electrodes. To produce reliable electrochemical signals, nano-liposomes which were loaded with Cd(II) and Cu(II) cations and decorated with antibodies specific for EGFR and VEGF were used as an efficient tool for detection of target biomarkers. In the analysis step, potentiometric striping analysis (PSA), as an electrochemical technique, was utilized for sensitive determination of these cations. The limits of detection (LODs) of EGFR and VEGF analyses were found to be 0.01 and 0.005 pg mL -1 with the linear dynamic ranges (LDRs) of 0.05-50000 and 0.01-7000 pg mL -1 , respectively. Moreover, the proposed biosensor was successfully used for sensitive, reproducible, and specific detection of EGFR and VEGF in real samples. Due to the SPE nature of the developed biosensor, we envision that this sensing tool has capability of being integrated with lab-on-a-chip (LOC), microfluidics, and micro total analysis systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Facile synthesis of amorphous FeOOH/MnO2 composites as screen-printed electrode materials for all-printed solid-state flexible supercapacitors

NASA Astrophysics Data System (ADS)

Lu, Qiang; Liu, Li; Yang, Shuanglei; Liu, Jun; Tian, Qingyong; Yao, Weijing; Xue, Qingwen; Li, Mengxiao; Wu, Wei

2017-09-01

More convenience and intelligence life lead by flexible/wearable electronics requires innovation and hommization of power sources. Here, amorphous FeOOH/MnO2 composite as screen-printed electrode materials for supercapacitors (SCs) is synthesized by a facile method, and solid-state flexible SCs with aesthetic design are fabricated by fully screen-printed process on different substrates, including PET, paper and textile. The amorphous FeOOH/MnO2 composite shows a high specific capacitance and a good rate capability (350.2 F g-1 at a current density of 0.5 A g-1 and 159.5 F g-1 at 20 A g-1). It also possesses 95.6% capacitance retention even after 10 000 cycles. Moreover, the all-printed solid-state flexible SC device exhibits a high area specific capacitance of 5.7 mF cm-2 and 80% capacitance retention even after 2000 cycles. It also shows high mechanical flexibility. Simultaneously, these printed SCs on different substrates in series are capable to light up a 1.9 V yellow light emitting diode (LED), even after bending and stretching.

Photovoltaic and Impedance Spectroscopy Study of Screen-Printed TiO₂ Based CdS Quantum Dot Sensitized Solar Cells.

PubMed

Atif, M; Farooq, W A; Fatehmulla, Amanullah; Aslam, M; Ali, Syed Mansoor

2015-01-19

Cadmium sulphide (CdS) quantum dot sensitized solar cells (QDSSCs) based on screen-printed TiO₂ were assembled using a screen-printing technique. The CdS quantum dots (QDs) were grown by using the Successive Ionic Layer Adsorption and Reaction (SILAR) method. The optical properties were studied by UV-Vis absorbance spectroscopy. Photovoltaic characteristics and impedance spectroscopic measurements of CdS QDSSCs were carried out under air mass 1.5 illuminations. The experimental results of capacitance against voltage indicate a trend from positive to negative capacitance because of the injection of electrons from the Fluorine doped tin oxide (FTO) electrode into TiO₂.

Disposable Screen Printed Electrochemical Sensors: Tools for Environmental Monitoring

PubMed Central

Hayat, Akhtar; Marty, Jean Louis

2014-01-01

Screen printing technology is a widely used technique for the fabrication of electrochemical sensors. This methodology is likely to underpin the progressive drive towards miniaturized, sensitive and portable devices, and has already established its route from “lab-to-market” for a plethora of sensors. The application of these sensors for analysis of environmental samples has been the major focus of research in this field. As a consequence, this work will focus on recent important advances in the design and fabrication of disposable screen printed sensors for the electrochemical detection of environmental contaminants. Special emphasis is given on sensor fabrication methodology, operating details and performance characteristics for environmental applications. PMID:24932865

Chemically Driven Printed Textile Sensors Based on Graphene and Carbon Nanotubes

PubMed Central

Skrzetuska, Ewa; Puchalski, Michał; Krucińska, Izabella

2014-01-01

The unique properties of graphene, such as the high elasticity, mechanical strength, thermal conductivity, very high electrical conductivity and transparency, make them it an interesting material for stretchable electronic applications. In the work presented herein, the authors used graphene and carbon nanotubes to introduce chemical sensing properties into textile materials by means of a screen printing method. Carbon nanotubes and graphene pellets were dispersed in water and used as a printing paste in the screen printing process. Three printing paste compositions were prepared—0%, 1% and 3% graphene pellet content with a constant 3% carbon nanotube mass content. Commercially available materials were used in this process. As a substrate, a twill woven cotton fabric was utilized. It has been found that the addition of graphene to printing paste that contains carbon nanotubes significantly enhances the electrical conductivity and sensing properties of the final product. PMID:25211197

Screen printed silver top electrode for efficient inverted organic solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Junwoo; Duraisamy, Navaneethan; Lee, Taik-Min

2015-10-15

Highlights: • Screen printing of silver pattern. • X-ray diffraction pattern confirmed the face centered cubic structure of silver. • Uniform surface morphology of silver pattern with sheet resistance of 0.06 Ω/sq. • The power conversion efficiency of fabricated solar cell is found to be 2.58%. - Abstract: The present work is mainly focused on replacement of the vacuum process for top electrode fabrication in organic solar cells. Silver top electrode deposited through solution based screen printing on pre-deposited polymeric thin film. The solution based printing technology provides uniform top electrode without damaging the underlying organic layers. The surface crystallinitymore » and surface morphology of silver top electrode are examined through X-ray diffraction, field-emission scanning electron microscope and atomic force microscope. The purity of silver is examined through X-ray energy dispersive spectroscopy. The top electrode exhibits face centered cubic structure with homogeneous morphology. The sheet resistance of top electrode is found to be 0.06 Ω/sq and an average pattern thickness of ∼15 μm. The power conversion efficiency is 2.58%. Our work demonstrates that the solution based screen printing is a significant role in the replacement of vacuum process for the fabrication of top electrode in organic solar cells.« less

Biocompatible patterning of proteins on wettability gradient surface by thermo-transfer printing.

PubMed

Kim, Sungho; Ryu, Yong-Sang; Suh, Jeng-Hun; Keum, Chang-Min; Sohn, Youngjoo; Lee, Sin-Doo

2014-08-01

We develop a simple and biocompatible method of patterning proteins on a wettability gradient surface by thermo-transfer printing. The wettability gradient is produced on a poly(dimethylsiloxane) (PDMS)-modified glass substrate through the temperature gradient during thermo-transfer printing. The water contact angle on the PDMS-modified surface is found to gradually increase along the direction of the temperature gradient from a low to a high temperature region. Based on the wettability gradient, the gradual change in the adsorption and immobilization of proteins (cholera toxin B subunit) is achieved in a microfluidic cell with the PDMS-modified surface.

Application of semiconductor diffusants to solar cells by screen printing

NASA Technical Reports Server (NTRS)

Evans, J. C., Jr.; Brandhorst, H. W., Jr.; Mazaris, G. A.; Scudder, L. R. (Inventor)

1978-01-01

Diffusants were applied onto semiconductor solar cell substrates, using screen printing techniques. The method was applicable to square and rectangular cells and can be used to apply dopants of opposite types to the front and back of the substrate. Then, simultaneous diffusion of both dopants can be performed with a single furnace pass.

Screen-printed calcium-birnessite electrodes for water oxidation at neutral pH and an "electrochemical harriman series".

PubMed

Lee, Seung Y; González-Flores, Diego; Ohms, Jonas; Trost, Tim; Dau, Holger; Zaharieva, Ivelina; Kurz, Philipp

2014-12-01

A mild screen-printing method was developed to coat conductive oxide surfaces (here: fluorine-doped tin oxide) with micrometer-thick layers of presynthesized calcium manganese oxide (Ca-birnessite) particles. After optimization steps concerning the printing process and layer thickness, electrodes were obtained that could be used as corrosion-stable water-oxidizing anodes at pH 7 to yield current densities of 1 mA cm(-2) at an overpotential of less than 500 mV. Analyses of the electrode coatings of optimal thickness (≈10 μm) indicated that composition, oxide phase, and morphology of the synthetic Ca-birnessite particles were hardly affected by the screen-printing procedure. However, a more detailed analysis by X-ray absorption spectroscopy revealed small modifications of both the Mn redox state and the structure at the atomic level, which could affect functional properties such as proton conductivity. Furthermore, the versatile new screen-printing method was used for a comparative study of various transition-metal oxides concerning electrochemical water oxidation under "artificial leaf conditions" (neutral pH, fairly low overpotential and current density), for which a general activity ranking of RuO2 >Co3 O4 ≈(Ca)MnOx ≈NiO was observed. Within the group of screened manganese oxides, Ca-birnessite performed better than "Mn-only materials" such as Mn2 O3 and MnO2 . © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Printing Processes Used to Manufacture Photovoltaic Solar Cells

ERIC Educational Resources Information Center

Rardin, Tina E.; Xu, Renmei

2011-01-01

There is a growing need for renewable energy sources, and solar power is a good option in many instances. Photovoltaic solar panels are now being manufactured via various methods, and different printing processes are being incorporated into the manufacturing process. Screen printing has been used most prevalently in the printing process to make…

An eye movement study for identification of suitable font characters for presentation on a computer screen.

PubMed

Banerjee, Jayeeta; Majumdar, Dhurjati; Majumdar, Deepti; Pal, Madhu Sudan

2010-06-01

We are experiencing a shifting of media: from the printed paper to the computer screen. This transition is modifying the process of how we read and understand a text. It is very difficult to conclude on suitability of font characters based upon subjective evaluation method only. Present study evaluates the effect of font type on human cognitive workload during perception of individual alphabets on a computer screen. Twenty six young subjects volunteered for this study. Here, subjects have been shown individual characters of different font types and their eye movements have been recorded. A binocular eye movement recorder was used for eye movement recording. The results showed that different eye movement parameters such as pupil diameter, number of fixations, fixation duration were less for font type Verdana. The present study recommends the use of font type Verdana for presentation of individual alphabets on various electronic displays in order to reduce cognitive workload.

Embedded Disposable Functionalized Electrochemical Biosensor with a 3D-Printed Flow Cell for Detection of Hepatic Oval Cells (HOCs).

PubMed

Damiati, Samar; Peacock, Martin; Leonhardt, Stefan; Damiati, Laila; Baghdadi, Mohammed A; Becker, Holger; Kodzius, Rimantas; Schuster, Bernhard

2018-02-14

Hepatic oval cells (HOCs) are considered the progeny of the intrahepatic stem cells that are found in a small population in the liver after hepatocyte proliferation is inhibited. Due to their small number, isolation and capture of these cells constitute a challenging task for immunosensor technology. This work describes the development of a 3D-printed continuous flow system and exploits disposable screen-printed electrodes for the rapid detection of HOCs that over-express the OV6 marker on their membrane. Multiwall carbon nanotube (MWCNT) electrodes have a chitosan film that serves as a scaffold for the immobilization of oval cell marker antibodies (anti-OV6-Ab), which enhance the sensitivity of the biomarker and makes the designed sensor specific for oval cells. The developed sensor can be easily embedded into the 3D-printed flow cell to allow cells to be exposed continuously to the functionalized surface. The continuous flow is intended to increase capture of most of the target cells in the specimen. Contact angle measurements were performed to characterize the nature and quality of the modified sensor surface, and electrochemical measurements (cyclic voltammetry (CV) and square wave voltammetry (SWV)) were performed to confirm the efficiency and selectivity of the fabricated sensor to detect HOCs. The proposed method is valuable for capturing rare cells and could provide an effective tool for cancer diagnosis and detection.

Automated toxicological screening reports of modified Agilent MSD Chemstation combined with Microsoft Visual Basic application programs.

PubMed

Choe, Sanggil; Kim, Suncheun; Choi, Hyeyoung; Choi, Hwakyoung; Chung, Heesun; Hwang, Bangyeon

2010-06-15

Agilent GC-MS MSD Chemstation offers automated library search report for toxicological screening using total ion chromatogram (TIC) and mass spectroscopy in normal mode. Numerous peaks appear in the chromatogram of biological specimen such as blood or urine and often large migrating peaks obscure small target peaks, in addition, any target peaks of low abundance regularly give wrong library search result or low matching score. As a result, retention time and mass spectrum of all the peaks in the chromatogram have to be checked to see if they are relevant. These repeated actions are very tedious and time-consuming to toxicologists. MSD Chemstation software operates using a number of macro files which give commands and instructions on how to work on and extract data from the chromatogram and spectroscopy. These macro files are developed by the own compiler of the software. All the original macro files can be modified and new macro files can be added to the original software by users. To get more accurate results with more convenient method and to save time for data analysis, we developed new macro files for reports generation and inserted new menus in the Enhanced Data Analysis program. Toxicological screening reports generated by these new macro files are in text mode or graphic mode and these reports can be generated with three different automated subtraction options. Text reports have Brief mode and Full mode and graphic reports have the option with or without mass spectrum mode. Matched mass spectrum and matching score for detected compounds are printed in reports by modified library searching modules. We have also developed an independent application program named DrugMan. This program manages drug groups, lists and parameters that are in use in MSD Chemstation. The incorporation of DrugMan with modified macro modules provides a powerful tool for toxicological screening and save a lot of valuable time on toxicological work. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

AN EXPERIMENTAL INVESTIGATION OF MICROPRINTING BY THE OFFSET METHOD.

DTIC Science & Technology

Continuous tone original art was photographed to produce a screened negative which was contact printed. The fullscale positive halftone was...photographically reduced 5.55 X to make a second negative which was contact printed on the offset plate. This reduction was equivalent to printing halftones ...reduced and printed. Macroscopic examination of printed materials mentioned above indicated that the halftones were good enough for identification in P

Coffee-Ring-Free Quantum Dot Thin Film Using Inkjet Printing from a Mixed-Solvent System on Modified ZnO Transport Layer for Light-Emitting Devices.

PubMed

Jiang, Congbiao; Zhong, Zhiming; Liu, Baiquan; He, Zhiwei; Zou, Jianhua; Wang, Lei; Wang, Jian; Peng, JunBiao; Cao, Yong

2016-10-05

Inkjet printing has been considered an available way to achieve large size full-color RGB quantum dots LED display, and the key point is to obtain printed film with uniform and flat surface profile. In this work, mixed solvent of 20 vol % 1,2-dichlorobenzene (oDCB) with cyclohexylbenzene (CHB) was used to dissolve green quantum dots (QDs) with CdSe@ZnS/ZnS core/shell structure. Then, by inkjet printing, a flat dotlike QDs film without the coffee ring was successfully obtained on polyetherimide (PEI)-modified ZnO layer, and the printed dots array exhibited great stability and repeatability. Here, adding oDCB into CHB solutions was used to reduce surface tension, and employing ZnO nanoparticle layer with PEI-modified was used to increase the surface free energy. As a result, a small contact angle is formed, which leads to the enhancement of evaporation rate, and then the coffee ring effect was suppressed. The printed dots with flat surface profile were eventually realized. Moreover, inverted green QD-LEDs with PEI-modified ZnO film as electron transport layer (ETL) and printed green QDs film as emission layer were successfully fabricated. The QD-LEDs exhibited the maximum luminance of 12 000 cd/m 2 and the peak current efficiency of 4.5 cd/A at luminance of 1500 cd/m 2 .

A Reverse Stroop Task with Mouse Tracking.

PubMed

Yamamoto, Naohide; Incera, Sara; McLennan, Conor T

2016-01-01

In a reverse Stroop task, observers respond to the meaning of a color word irrespective of the color in which the word is printed-for example, the word red may be printed in the congruent color (red), an incongruent color (e.g., blue), or a neutral color (e.g., white). Although reading of color words in this task is often thought to be neither facilitated by congruent print colors nor interfered with incongruent print colors, this interference has been detected by using a response method that does not give any bias in favor of processing of word meanings or processing of print colors. On the other hand, evidence for the presence of facilitation in this task has been scarce, even though this facilitation is theoretically possible. By modifying the task such that participants respond to a stimulus color word by pointing to a corresponding response word on a computer screen with a mouse, the present study investigated the possibility that not only interference but also facilitation would take place in a reverse Stroop task. Importantly, in this study, participants' responses were dynamically tracked by recording the entire trajectories of the mouse. Arguably, this method provided richer information about participants' performance than traditional measures such as reaction time and accuracy, allowing for more detailed (and thus potentially more sensitive) investigation of facilitation and interference in the reverse Stroop task. These trajectories showed that the mouse's approach toward correct response words was significantly delayed by incongruent print colors but not affected by congruent print colors, demonstrating that only interference, not facilitation, was present in the current task. Implications of these findings are discussed within a theoretical framework in which the strength of association between a task and its response method plays a critical role in determining how word meanings and print colors interact in reverse Stroop tasks.

The impact of tailored interventions on a community health center population.

PubMed

Rimer, B K; Conaway, M; Lyna, P; Glassman, B; Yarnall, K S; Lipkus, I; Barber, L T

1999-06-01

We conducted a 4-year randomized study in a community health center that serves primarily low income Blacks in Durham, North Carolina. Patients (1318 at baseline) were assigned randomly to one of three study groups: provider prompting intervention alone, provider prompting and tailored print materials or the previous group and tailored telephone counseling. The purpose of the study was to determine whether increasingly intensive, tailored print and telephone interventions also were increasingly effective in promoting adherence to mammograms, Pap tests and overall cancer screening compliance. Thus, the combination of tailored print interventions (print and telephone) should have been more effective than the provider prompting intervention alone, or the print intervention and prompting combination. This is one of the few studies to examine a measure of overall cancer screening compliance and to assess the benefit of combinations of tailored interventions in promoting adherence to cancer screening. Patients gave extremely high ratings to the interventions. At the bivariate level, we found a significant effect of the most intensive group (provider prompting intervention, tailored print communications and tailored telephone counseling) on Pap test compliance (P = 0.05) and borderline significance at the multivariate level (P = 0.06) as well on overall screening compliance (P = 0.06). There was not a significant effect on mammography, probably because a majority of the patients were receiving regular mammograms. We also found some important subgroup differences. For example, a larger proportion of women reported Pap tests in the tailored print and counseling group when they believed the materials were 'meant for me.' These results show that a combination of tailored interventions may have potential for reaching the women who have too often been labeled the 'hard to reach.'

Development of gold nanoparticles modified screen-printed carbon electrode for the analysis of thiram, disulfiram and their derivative in food using ultra-high performance liquid chromatography.

PubMed

Charoenkitamorn, Kanokwan; Chailapakul, Orawon; Siangproh, Weena

2015-01-01

For the first time, gold nanoparticles (AuNPs) modified screen-printed carbon electrode (SPCE) was developed as working electrode in ultra-high performance liquid chromatography (UHPLC) coupled with electrochemical detection (UHPLC-ED) for simultaneous determination of thiram, disulfiram, and N,N-diethyl-N',N'-dimethylthiuram disulfide, their derivative compound. The separation was performed in reversed-phase mode using C18 column, mobile phase consisting of 55:45 (v/v) ratio of 0.05 M phosphate buffer solution (pH 5) and acetonitrile at a flow rate of 1.5 mL min(-1). For the detection part, the amperometric detection was chosen with a detection potential of 1.2 V vs. Ag/AgCl. Under the optimal conditions, the good linear relationship was obtained in the range of 0.07-15, 0.07-12, and 0.5-15 µg mL(-1) (correlation coefficient more than 0.9900) for thiram, N,N-diethyl-N',N'-dimethylthiuram disulfide, and disulfiram, respectively. The limits of detection (LODs) of thiram, N,N-diethyl-N',N'-dimethylthiuram disulfide, and disulfiram were 0.022, 0.023, and 0.165 µg mL(-1), respectively. Moreover, this method was successfully applied for the detection of these compounds in real samples (apple, grape and lettuce) with the recoveries ranging from 94.3% to 108.8%. To validate this developed method, a highly quantitative agreement was clearly observed compared to standard UHPLC-UV system. Therefore, the proposed electrode can be effectively used as an alternative electrode in UHPLC-ED for rapid, selective, highly sensitive, and simultaneous determination of thiram, disulfiram, and N,N-diethyl-N',N'-dimethylthiuram disulfide. Copyright © 2014 Elsevier B.V. All rights reserved.

International Communique. . . About Information, People, Places, Things. Printing Processes Issue P-8B.

ERIC Educational Resources Information Center

Peace Corps, Washington, DC. Information Collection and Exchange Div.

Focusing on the production and utilization of printing processes in constructing effective visuals for teaching, this bulletin contains articles on the silk screening stencil process, use of a similar process with a portable mimeograph, and the hectograph process. The first article lists equipment needed to make a silk screen, steps in building…

Screen printed Y and Bi-based superconductors

NASA Technical Reports Server (NTRS)

Haertling, Gene H.; Hsi, Chi-Shiung

1992-01-01

High T(sub c) superconducting thick film was prepared by screen printing process. Y-based (YBa2Cu3O(7 - x)) superconducting thick films were printed on 211/Al2O3, SNT/Al2O3, and YSZ substrates. Because of poor adhesion of the superconducting thick films to 211/Al2O3 and SNT/Al2O3 substrates, relatively low T(sub c) and J(sub c) values were obtained from the films printed on these substrates. Critical temperatures of YBa2Cu3O(7 - x) thick films deposited on 211/Al2O3 and SNT/Al2O3 substrates were about 80 K. The critical current densities of these films were less than 2 A/cm(exp 2). Higher T(sub c) and J(sub c) films were printed on the YSZ substrates; T(sub c) = 86.4 K and J(sub c) = 50.4 A/cm(exp 2). Multiple lead samples were also prepared on the YSZ substrates. These showed lower T(sub c) and J(sub c) values than plain samples. The heat treatment conditions of the multiple lead samples are still under investigation. Bi-based superconductor thick films have been obtained so far. Improving the superconducting properties of the BSCCO screen printed thick films will be emphasized in future work.

Monolithic quasi-solid-state dye-sensitized solar cells based on graphene-modified mesoscopic carbon-counter electrodes

NASA Astrophysics Data System (ADS)

Rong, Yaoguang; Han, Hongwei

2013-01-01

A monolithic quasi-solid-state dye-sensitized solar cell (DSSC) based on graphene-modified mesoscopic carbon-counter electrode is developed. A TiO2-working electrode layer, ZrO2 spacer layer, and carbon counter electrode layer were constructed on a single conducting glass substrate by screen printing. The quasi-solid-state polymer gel electrolyte employed a polymer composite as the gelator, and effectively infiltrated the porous layers. Fabricated with normal carbon-counter electrode (NC-CE) containing graphite and carbon black, the DSSC had a power conversion efficiency (PCE) of 5.09% with the fill factor of 0.63 at 100 mW cm-2 AM1.5 illumination. When the NC-CE was modified with graphene sheets, the PCE and fill factor were enhanced to 6.27% and 0.71, respectively. This improvement indicates excellent conductivity and high electrocatalytic activity of the graphene sheets, which have been considered as a promising platinum-free electrode material for DSSCs.

Random vibration (stress screening) of printed wiring assemblies

NASA Technical Reports Server (NTRS)

Bastien, Gilbert J.

1988-01-01

The results of a random vibration test screening (RVSS) study of the determination of the upper and lower vibration limits on printed wiring assemblies (PWA) are summarized. The study results are intended to serve as a guide for engineers and designers who make decisions on PWA features that need to withstand the stresses of dynamic testing and screening. The maximum allowable PWA deflection, G levels, and PSD levels are compared to the expected or actual levels to determine if deleterious effects will occur.

Smartphone-based portable biosensing system using impedance measurement with printed electrodes for 2,4,6-trinitrotoluene (TNT) detection.

PubMed

Zhang, Diming; Jiang, Jing; Chen, Junye; Zhang, Qian; Lu, Yanli; Yao, Yao; Li, Shuang; Logan Liu, Gang; Liu, Qingjun

2015-08-15

Rapid, sensitive, selective and portable detection of 2,4,6-trinitrotoluene (TNT) is in high demand for public safety and environmental monitoring. In this study, we reported a smartphone-based system using impedance monitoring for TNT detection. The screen-printed electrodes modified with TNT-specific peptides were used as disposable a biosensor to produce impedance responses to TNT. The responses could be monitored by a hand-held device and send out to smartphone through Bluetooth. Then, the smartphone was used to display TNT responses in real time and report concentration finally. In the measurement, the system was demonstrated to detect TNT at concentration as low as 10(-6) M and distinguish TNT versus different chemicals in high specificity. Thus, the smartphone-based biosensing platform provided a convenient and efficient approach to design portable instruments for chemical detections such as TNT recognition. Copyright © 2015 Elsevier B.V. All rights reserved.

Record high efficiency of screen-printed silicon aluminum back surface field solar cell: 20.29%

NASA Astrophysics Data System (ADS)

Kim, Ki Hyung; Park, Chang Sub; Doo Lee, Jae; Youb Lim, Jong; Yeon, Je Min; Kim, Il Hwan; Lee, Eun Joo; Cho, Young Hyun

2017-08-01

We have achieved a record high cell efficiency of 20.29% for an industrial 6-in. p-type monocrystalline silicon solar cell with a full-area aluminum back surface field (Al-BSF) by simply modifying the cell structure and optimizing the process with the existing cell production line. The cell efficiency was independently confirmed by the Solar Energy Research Institute of Singapore (SERIS). To increase the cell efficiency, for example, in four busbars, double printing, a lightly doped emitter with a sheet resistance of 90 to 100 Ω/□, and front surface passivation by using silicon oxynitride (SiON) on top of a silicon nitride (SiN x ) antireflection layer were adopted. To optimize front side processing, PC1D simulation was carried out prior to cell fabrication. The resulting efficiency gain is 0.64% compared with that in the reference cells with three busbars, a single antireflection coating layer, and a low-sheet-resistance emitter.

Dendrimer enriched single-use aptasensor for impedimetric detection of activated protein C.

PubMed

Erdem, Arzum; Congur, Gulsah

2014-05-01

A novel impedimetric aptasensor for detection of human activated protein C (APC) was introduced for the first time in the present study. An enhanced sensor response was obtained using poly(amidoamine) (PAMAM) dendrimer having 16 succinamic acid surface groups (generation 2, G2-PS), that was modified onto the surface of screen printed graphite electrode (G2-PS/SPE). An amino modified DNA aptamer was then immobilized onto the surface of G2-PS modified SPE. The selective interaction of APT with its cognate protein, APC was investigated using different electrochemical techniques; differential pulse voltammetry (DPV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The microscopic characterization was consecutively performed before/after each modification/interaction step using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The selectivity of aptasensor was tested in the presence of numerous proteins; protein C, thrombin, bovine serum albumin, factor Va and chromogenic substrate in different buffer mediums. The APC detection in the artificial serum; fetal bovine serum (FBS) was also performed impedimetrically. This dendrimer modified aptasensor technology brings several advantages: being single-use, fast screening with low-cost per measurement and resulting in sensitive detection of APC with the detection limits of 0.74 μg/mL (0.46 pmol in 35 μL sample) in buffer medium, and 2.03 μg/mL (1.27 pmol in 35 μL sample) in serum. Copyright © 2014 Elsevier B.V. All rights reserved.

No Offset Press? No Problem--Teach Duotone Production with Screen Printing

ERIC Educational Resources Information Center

Hersey, Cara L.

2006-01-01

Teachers can integrate halftone or duotone production into a graphic communications class even if they lack access to an offset press. The approach described in this article, in fact, offers a benefit in that the dots involved in screen printing halftones and dutones can be enlarged to make them easily visible, while those used in offset printing…

Effect of Screen Reading and Reading from Printed Out Material on Student Success and Permanency in Introduction to Computer Lesson

ERIC Educational Resources Information Center

Tuncer, Murat; Bahadir, Ferdi

2014-01-01

In this study, the effect of screen reading and reading from printed out material on student success and permanency in Introduction to Computer Lesson is investigated. Study group of the research consists of 78 freshman students registered in Erzincan University Refahiye Vocational School Post Service department. Study groups of research consist…

Fire resistant films for aircraft applications

NASA Technical Reports Server (NTRS)

Kourtides, D. A.

1983-01-01

Alternative sandwich panel decorative films were investigated as replacements for the polyvinyl fluoride currently used in aircraft interiors. Candidate films were studied for flammability, smoke emission, toxic gas emission, flame spread, and suitability as a printing surface for the decorative acrylic ink system. Several of the candidate films tested were flame modified polyvinyl fluoride, polyvinylidene fluoride, polyimide, polyamide, polysulfone, polyphenylsulfone, polyethersulfone, polybenzimidazole, polycarbonate, polyparabanic acid, polyphosphazene, polyetheretherketon, and polyester. The films were evaluated as pure films only, films silk-screened with an acrylic ink, and films adhered to a phenolic fiberglass substrate. Films which exhibited the highest fire resistant properties included PEEK polyetheretherketon, Aramid polyamide, and ISO-BPE polyester.

Polymer film strain gauges for measuring large elongations

NASA Astrophysics Data System (ADS)

Kondratov, A. P.; Zueva, A. M.; Varakin, R. S.; Taranec, I. P.; Savenkova, I. A.

2018-02-01

The paper shows the possibility to print polymer strain gages, microstrip lines, coplanar waveguides, and other prints for avionics using printing technology and equipment. The methods of screen and inkjet printing have been complemented by three new operations of preparing print films for application of an electrically conductive ink layer. Such additional operations make it possible to enhance the conductive ink layer adhesion to the film and to manufacture strain gages for measuring large elongations.

Effect of providing risk information on undergoing cervical cancer screening: a randomized controlled trial.

PubMed

Fujiwara, Hiroyuki; Shimoda, Akihiro; Ishikawa, Yoshiki; Taneichi, Akiyo; Ohashi, Mai; Takahashi, Yoshifumi; Koyanagi, Takahiro; Morisawa, Hiroyuki; Takahashi, Suzuyo; Sato, Naoto; Machida, Shizuo; Takei, Yuji; Saga, Yasushi; Suzuki, Mitsuaki

2015-01-01

In Japan, the cervical cancer screening rate is extremely low. Towards improving the cervical cancer screening rate, encouraging eligible people to make an informed choice, which is a decision-making process that relies on beliefs informed by adequate information about the possible benefits and risks of screening, has attracted increased attention in the public health domain. However, there is concern that providing information on possible risks of screening might prevent deter from participating. In total, 1,912 women aged 20-39 years who had not participated in screening in the fiscal year were selected from a Japanese urban community setting. Participants were randomly divided into 3 groups. Group A received a printed reminder with information about the possible benefits of screening, group B received a printed reminder with information about possible benefits and risks, and group C received a printed reminder with simple information only (control group). Out of 1,912 participants, 169 (8.8%) participated in cervical cancer screening. In the intervention groups, 137 (10.9%) participated in cervical cancer screening, compared to only 32 (4.9%) of the control group (p < 0.001). In addition, logistic regression analysis revealed that there was no significant difference in screening rate between group A and group B (p = 0.372). Providing information on the possible risks of screening may not prevent people from taking part in cervical cancer screening among a Japanese non-adherent population.

Print2Screen Mobile App: Embedding Multimedia in Printed ODL Course Materials Using QR Codes

ERIC Educational Resources Information Center

Abeywardena, Ishan Sudeera

2017-01-01

With the rise of OER and multimedia such as YouTube videos, many academic institutions are becoming mindful of the richness they bring into the teaching and learning process. Given that multimedia resources cannot be directly integrated into printed material, the only available alternative is to print hyperlinks, which teachers and learners can…

Recruitment techniques for alcohol pharmacotherapy clinical trials: A cost-benefit analysis.

PubMed

Tompkins, D Andrew; Sides, Jessica A; Harrison, Joseph A; Strain, Eric C

2015-12-01

Alcohol use disorders (AUDs) represent a large public health burden with relatively few efficacious pharmacotherapies. Randomized controlled trials (RCTs) for new AUD therapies can be hampered by ineffective recruitment, leading to increased trial costs. The current analyses examined the effectiveness of recruitment efforts during two consecutive outpatient RCTs of novel AUD pharmacotherapies conducted between 2009 and 2012. During an initial phone screen, participants identified an ad source for learning about the study. Qualified persons were then scheduled for in-person screens. The present analyses examined demographic differences amongst the eight ad sources utilized. Recruitment effectiveness was determined by dividing the number of persons meeting criteria for an in-person screen by the total number of callers from each ad source. Cost-effectiveness was determined by dividing total ad source cost by number of screens, participants randomized, and completers. 1,813 calls resulted in 1,005 completed phone screens. The most common ad source was TV (34%), followed by print (29%), word-of-mouth (11%), flyer (8%), internet (5%), radio (5%), bus ad (2%), and billboard (1%). Participants reporting bus ads (46%), billboard (44%), or print ads (34%) were significantly more likely than the other sources to meet criteria to be scheduled for in-person screens. The most cost-effective ad source was print ($2,506 per completer), while bus ad was the least cost-effective ($13,376 per completer). Recruitment in AUD RCTs can be successful using diverse advertising methods. The present analyses favored use of print ads as most cost-effective.

Screen printing technology applied to silicon solar cell fabrication

NASA Technical Reports Server (NTRS)

Thornhill, J. W.; Sipperly, W. E.

1980-01-01

The process for producing space qualified solar cells in both the conventional and wraparound configuration using screen printing techniques was investigated. Process modifications were chosen that could be easily automated or mechanized. Work was accomplished to optimize the tradeoffs associated with gridline spacing, gridline definition and junction depth. An extensive search for possible front contact metallization was completed. The back surface field structures along with the screen printed back contacts were optimized to produce open circuit voltages of at least an average of 600 millivolts. After all intended modifications on the process sequence were accomplished, the cells were exhaustively tested. Electrical tests at AMO and 28 C were made before and after boiling water immersion, thermal shock, and storage under conditions of high temperature and high humidity.

Automated fabrication of back surface field silicon solar cells with screen printed wraparound contacts

NASA Technical Reports Server (NTRS)

Thornhill, J. W.

1977-01-01

The development of a process for fabricating 2 x 4 cm back surface field silicon solar cells having screen printed wraparound contacts is described. This process was specifically designed to be amenable for incorporation into the automated nonvacuum production line. Techniques were developed to permit the use of screen printing for producing improved back surface field structures, wraparound dielectric layers, and wraparound contacts. The optimized process sequence was then used to produce 1852 finished cells. Tests indicated an average conversion efficiency of 11% at AMO and 28 C, with an average degradation of maximum power output of 1.5% after boiling water immersion or thermal shock cycling. Contact adherence was satisfactory after these tests, as well as long term storage at high temperature and high humidity.

Non-invasive toluene sensor for early diagnosis of lung cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saxena, Rahul; Srivastava, Sudha, E-mail: sudha.srivastava@jiit.ac.in

Here we present, quantification of volatile organic compounds in human breath for early detection of lung cancer to increase survival probability. Graphene oxide nanosheets synthesized by modified Hummer’s method were employed as a sensing element to detect the presence of toluene in the sample. Optical and morphological characterization of synthesized nanomaterial was performed by UV-Visible spectroscopy and scanning electron microscopy (SEM) respectively. Spectroscopic assay shows a linearly decreasing intensity of GO absorption peak with increasing toluene concentration with a linear range from 0-200 pM. While impedimetric sensor developed on a graphene oxide nanosheetsmodified screen printed electrodes displayed a decreasing electronmore » transfer resistance increasing toluene with much larger linear range of 0-1000 pM. Reported techniques are advantageous as these are simple, sensitive and cost effective, which can easily be extended for primary screening of other VOCs.« less

A smart approach to add antibacterial functionality to cellulosic pigment prints.

PubMed

Ibrahim, N A; Eid, B M; Elmaaty, T M Abou; El-Aziz, E Abd

2013-04-15

This study was devoted to enhancing the antibacterial functionality of pigment printed cotton, linen and viscose fabrics. Ag-NP's/PVP colloid, triclosan derivatives, chitosan or choline chloride was successfully incorporated into the pigment paste followed by printing and microwave curing to impart antibacterial activity to the cellulosic prints. Results obtained demonstrate that the modified pigment prints exhibit a remarkable antibacterial activity against the G+ve (Staphylococcus aureus) and G-ve (Escherichia coli) bacteria with a noticeable durability after 20 washing cycles without adversely affecting the printing and softness properties. The extent of printability and functionality of the nominated substrates are significantly governed by the type of: bio-active ingredient, binder, pigment and substrate. TEM, SEM and EDX analysis confirmed the formation of Ag-NP's/PVP colloid, of particle size range 7-14 nm, deposition of cross-linked-binder film onto the modified pigment prints, and the existence of elementary Ag and Si loaded onto fabrics surface, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of pigment concentration on fastness and color values of thermal and UV curable pigment printing

NASA Astrophysics Data System (ADS)

Baysal, Gulcin; Kalav, Berdan; Karagüzel Kayaoğlu, Burçak

2017-10-01

In the current study, it is aimed to determine the effect of pigment concentration on fastness and colour values of thermal and ultraviolet (UV) curable pigment printing on synthetic leather. For this purpose, thermal curable solvent-based and UV curable water-based formulations were prepared with different pigment concentrations (3, 5 and 7%) separately and applied by screen printing technique using a screen printing machine. Samples printed with solvent-based formulations were thermally cured and samples printed with water-based formulations were cured using a UV curing machine equipped with gallium and mercury (Ga/Hg) lamps at room temperature. The crock fastness values of samples printed with solvent-based formulations showed that increase in pigment concentration was not effective on both dry and wet crock fastness values. On the other hand, in samples printed with UV curable water-based formulations, dry crock fastness was improved and evaluated as very good for all pigment concentrations. However, increasing the pigment concentration affected the wet crock fastness values adversely and lower values were observed. As the energy level increased for each irradiation source, the fastness values were improved. In comparison with samples printed with solvent-based formulations, samples printed with UV curable water-based formulations yielded higher K/S values at all pigment concentrations. The results suggested that, higher K/S values can be obtained in samples printed with UV curable water-based formulations at a lower pigment concentration compared to samples printed with solvent-based formulations.

Screen printed flexible radiofrequency identification tag for oxygen monitoring.

PubMed

Martínez-Olmos, A; Fernández-Salmerón, J; Lopez-Ruiz, N; Rivadeneyra Torres, A; Capitan-Vallvey, L F; Palma, A J

2013-11-19

In this work, a radiofrequency identification (RFID) tag with an optical indicator for the measurement of gaseous oxygen is described. It consists of an O2 sensing membrane of PtOEP together with a full electronic system for RFID communication, all printed on a flexible substrate. The membrane is excited by an LED at 385 nm wavelength and the intensity of the luminescence generated is registered by means of a digital color detector. The output data corresponding to the red coordinate of the RGB color space is directly related to the concentration of O2, and it is sent to a microcontroller. The RFID tag is designed and implemented by screen printing on a flexible substrate for the wireless transmission of the measurement to a remote reader. It can operate in both active and passive mode, obtaining the power supply from the electromagnetic waves of the RFID reader or from a small battery, respectively. This system has been fully characterized and calibrated including temperature drifts, showing a high-resolution performance that allows measurement of very low values of oxygen content. Therefore this system is perfectly suitable for its use in modified atmosphere packaging where the oxygen concentration is reduced below 2%. As the reading of the O2 concentration inside the envelope is carried out with an external RFID reader using wireless communication, there is no need for perforations for probes or wires, so the packaging remains completely closed. With the presented device, a limit of detection of 40 ppm and a resolution as low as 0.1 ppm of O2 can be reached with a low power consumption of 3.55 mA.

A Reverse Stroop Task with Mouse Tracking

PubMed Central

Yamamoto, Naohide; Incera, Sara; McLennan, Conor T.

2016-01-01

In a reverse Stroop task, observers respond to the meaning of a color word irrespective of the color in which the word is printed—for example, the word red may be printed in the congruent color (red), an incongruent color (e.g., blue), or a neutral color (e.g., white). Although reading of color words in this task is often thought to be neither facilitated by congruent print colors nor interfered with incongruent print colors, this interference has been detected by using a response method that does not give any bias in favor of processing of word meanings or processing of print colors. On the other hand, evidence for the presence of facilitation in this task has been scarce, even though this facilitation is theoretically possible. By modifying the task such that participants respond to a stimulus color word by pointing to a corresponding response word on a computer screen with a mouse, the present study investigated the possibility that not only interference but also facilitation would take place in a reverse Stroop task. Importantly, in this study, participants’ responses were dynamically tracked by recording the entire trajectories of the mouse. Arguably, this method provided richer information about participants’ performance than traditional measures such as reaction time and accuracy, allowing for more detailed (and thus potentially more sensitive) investigation of facilitation and interference in the reverse Stroop task. These trajectories showed that the mouse’s approach toward correct response words was significantly delayed by incongruent print colors but not affected by congruent print colors, demonstrating that only interference, not facilitation, was present in the current task. Implications of these findings are discussed within a theoretical framework in which the strength of association between a task and its response method plays a critical role in determining how word meanings and print colors interact in reverse Stroop tasks. PMID:27199881

A Comprehensive Surface Mount Technology Solution for Integrated Circuits onto Flexible Screen Printed Electrical Interconnects

DTIC Science & Technology

2014-05-19

their acceptable thermal stability, Polyimides have established as a conventional substrate material for flexible interconnects, which can be...of the silver flake ink for the screen-printed interconnects, the assembled unit fulfills biocompatibility requirements in a limited manner ([29...30]). Even though biocompatibility of substrate [31] is fulfilled, toxicity of the insulating mask [32] and encapsulation need to be considered

A Disposable Microfluidic Device with a Screen Printed Electrode for Mimicking Phase II Metabolism

PubMed Central

Vasiliadou, Rafaela; Nasr Esfahani, Mohammad Mehdi; Brown, Nathan J.; Welham, Kevin J.

2016-01-01

Human metabolism is investigated using several in vitro methods. However, the current methodologies are often expensive, tedious and complicated. Over the last decade, the combination of electrochemistry (EC) with mass spectrometry (MS) has a simpler and a cheaper alternative to mimic the human metabolism. This paper describes the development of a disposable microfluidic device with a screen-printed electrode (SPE) for monitoring phase II GSH reactions. The proposed chip has the potential to be used as a primary screening tool, thus complementing the current in vitro methods. PMID:27598162

3D-Printed Fluidic Devices for Nanoparticle Preparation and Flow-Injection Amperometry Using Integrated Prussian Blue Nanoparticle-Modified Electrodes

PubMed Central

Bishop, Gregory W.; Satterwhite, Jennifer E.; Bhakta, Snehasis; Kadimisetty, Karteek; Gillette, Kelsey M.; Chen, Eric; Rusling, James F.

2015-01-01

A consumer-grade fused filament fabrication (FFF) 3D printer was used to construct fluidic devices for nanoparticle preparation and electrochemical sensing. Devices were printed using poly(ethylene terephthalate) and featured threaded ports to connect polyetheretherketone (PEEK) tubing via printed fittings prepared from acrylonitrile butadiene styrene (ABS). These devices included channels designed to have 800 × 800 µm2 square cross sections and were semitransparent to allow visualization of the solution-filled channels. A 3D-printed device with a Y-shaped mixing channel was used to prepare Prussian blue nanoparticles (PBNPs) under flow rates of 100 to 2000 µL min−1. PBNPs were then attached to gold electrodes for hydrogen peroxide sensing. 3D-printed devices used for electrochemical measurements featured threaded access ports into which a fitting equipped with reference, counter, and PBNP-modified working electrodes could be inserted. PBNP-modified electrodes enabled amperometric detection of H2O2 in the 3D-printed channel by flow-injection analysis, exhibiting a detection limit of 100 nM and linear response up to 20 µM. These experiments show that a consumer-grade FFF printer can be used to fabricate low-cost fluidic devices for applications similar to those that have been reported with more expensive 3D-printing methods. PMID:25901660

Embedded Disposable Functionalized Electrochemical Biosensor with a 3D-Printed Flow Cell for Detection of Hepatic Oval Cells (HOCs)

PubMed Central

Peacock, Martin; Leonhardt, Stefan; Damiati, Laila; Baghdadi, Mohammed A.; Schuster, Bernhard

2018-01-01

Hepatic oval cells (HOCs) are considered the progeny of the intrahepatic stem cells that are found in a small population in the liver after hepatocyte proliferation is inhibited. Due to their small number, isolation and capture of these cells constitute a challenging task for immunosensor technology. This work describes the development of a 3D-printed continuous flow system and exploits disposable screen-printed electrodes for the rapid detection of HOCs that over-express the OV6 marker on their membrane. Multiwall carbon nanotube (MWCNT) electrodes have a chitosan film that serves as a scaffold for the immobilization of oval cell marker antibodies (anti-OV6-Ab), which enhance the sensitivity of the biomarker and makes the designed sensor specific for oval cells. The developed sensor can be easily embedded into the 3D-printed flow cell to allow cells to be exposed continuously to the functionalized surface. The continuous flow is intended to increase capture of most of the target cells in the specimen. Contact angle measurements were performed to characterize the nature and quality of the modified sensor surface, and electrochemical measurements (cyclic voltammetry (CV) and square wave voltammetry (SWV)) were performed to confirm the efficiency and selectivity of the fabricated sensor to detect HOCs. The proposed method is valuable for capturing rare cells and could provide an effective tool for cancer diagnosis and detection. PMID:29443890

Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kashiwagi, Y., E-mail: kasiwagi@omtri.or.jp; Yamamoto, M.; Saitoh, M.

2014-12-01

Transparent electrodes were formed on Eu-doped GaN-based red-light-emitting diode (GaN:Eu LED) substrates by the screen printing of indium tin oxide nanoparticle (ITO np) inks as a wet process. The ITO nps with a mean diameter of 25 nm were synthesized by the controlled thermolysis of a mixture of indium complexes and tin complexes. After the direct screen printing of ITO np inks on GaN:Eu LED substrates and sintering at 850 °C for 10 min under atmospheric conditions, the resistivity of the ITO film was 5.2 mΩ cm. The fabricated LED up to 3 mm square surface emitted red light when the on-voltage was exceeded.

Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode

NASA Astrophysics Data System (ADS)

Kashiwagi, Y.; Koizumi, A.; Takemura, Y.; Furuta, S.; Yamamoto, M.; Saitoh, M.; Takahashi, M.; Ohno, T.; Fujiwara, Y.; Murahashi, K.; Ohtsuka, K.; Nakamoto, M.

2014-12-01

Transparent electrodes were formed on Eu-doped GaN-based red-light-emitting diode (GaN:Eu LED) substrates by the screen printing of indium tin oxide nanoparticle (ITO np) inks as a wet process. The ITO nps with a mean diameter of 25 nm were synthesized by the controlled thermolysis of a mixture of indium complexes and tin complexes. After the direct screen printing of ITO np inks on GaN:Eu LED substrates and sintering at 850 °C for 10 min under atmospheric conditions, the resistivity of the ITO film was 5.2 mΩ cm. The fabricated LED up to 3 mm square surface emitted red light when the on-voltage was exceeded.

High-Performance Screen-Printed Thermoelectric Films on Fabrics

DOE PAGES

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook; ...

2017-08-04

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screenprinting of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5Sb 1.5Te 3 or n-type Bi 2Te 2.7Se 0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscositymore » for printability at a very small concentration (0.45–0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.« less

High-Performance Screen-Printed Thermoelectric Films on Fabrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screenprinting of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5Sb 1.5Te 3 or n-type Bi 2Te 2.7Se 0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscositymore » for printability at a very small concentration (0.45–0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.« less

Fabricating Simple Wax Screen-Printing Paper-Based Analytical Devices to Demonstrate the Concept of Limiting Reagent in Acid- Base Reactions

ERIC Educational Resources Information Center

Namwong, Pithakpong; Jarujamrus, Purim; Amatatongchai, Maliwan; Chairam, Sanoe

2018-01-01

In this article, a low-cost, simple, and rapid fabrication of paper-based analytical devices (PADs) using a wax screen-printing method is reported here. The acid-base reaction is implemented in the simple PADs to demonstrate to students the chemistry concept of a limiting reagent. When a fixed concentration of base reacts with a gradually…

A facile electrochemical intercalation and microwave assisted exfoliation methodology applied to screen-printed electrochemical-based sensing platforms to impart improved electroanalytical outputs.

PubMed

Pierini, Gastón D; Foster, Christopher W; Rowley-Neale, Samuel J; Fernández, Héctor; Banks, Craig E

2018-06-12

Screen-printed electrodes (SPEs) are ubiquitous with the field of electrochemistry allowing researchers to translate sensors from the laboratory to the field. In this paper, we report an electrochemically driven intercalation process where an electrochemical reaction uses an electrolyte as a conductive medium as well as the intercalation source, which is followed by exfoliation and heating/drying via microwave irradiation, and applied to the working electrode of screen-printed electrodes/sensors (termed EDI-SPEs) for the first time. This novel methodology results in an increase of up to 85% of the sensor area (electrochemically active surface area, as evaluated using an outer-sphere redox probe). Upon further investigation, it is found that an increase in the electroactive area of the EDI-screen-printed based electrochemical sensing platforms is critically dependent upon the analyte and its associated electrochemical mechanism (i.e. adsorption vs. diffusion). Proof-of-concept for the electrochemical sensing of capsaicin, a measure of the hotness of chillies and chilli sauce, within both model aqueous solutions and a real sample (Tabasco sauce) is demonstrated in which the electroanalytical sensitivity (a plot of signal vs. concentration) is doubled when utilising EDI-SPEs over that of SPEs.

Pencil It in: Exploring the Feasibility of Hand-Drawn Pencil Electrochemical Sensors and Their Direct Comparison to Screen-Printed Electrodes

PubMed Central

Bernalte, Elena; Foster, Christopher W.; Brownson, Dale A.C.; Mosna, Morgane; Smith, Graham C.; Banks, Craig E.

2016-01-01

We explore the fabrication, physicochemical characterisation (SEM, Raman, EDX and XPS) and electrochemical application of hand-drawn pencil electrodes (PDEs) upon an ultra-flexible polyester substrate; investigating the number of draws (used for their fabrication), the pencil grade utilised (HB to 9B) and the electrochemical properties of an array of batches (i.e, pencil boxes). Electrochemical characterisation of the PDEs, using different batches of HB grade pencils, is undertaken using several inner- and outer-sphere redox probes and is critically compared to screen-printed electrodes (SPEs). Proof-of-concept is demonstrated for the electrochemical sensing of dopamine and acetaminophen using PDEs, which are found to exhibit competitive limits of detection (3σ) upon comparison to SPEs. Nonetheless, it is important to note that a clear lack of reproducibility was demonstrated when utilising these PDEs fabricated using the HB pencils from different batches. We also explore the suitability and feasibility of a pencil-drawn reference electrode compared to screen-printed alternatives, to see if one can draw the entire sensing platform. This article reports a critical assessment of these PDEs against that of its screen-printed competitors, questioning the overall feasibility of PDEs’ implementation as a sensing platform. PMID:27589815

Recruitment techniques for alcohol pharmacotherapy clinical trials: A cost-benefit analysis

PubMed Central

Tompkins, D. Andrew; Sides, Jessica A.; Harrison, Joseph A.; Strain, Eric C.

2014-01-01

Objectives Alcohol use disorders (AUDs) represent a large public health burden with relatively few efficacious pharmacotherapies. Randomized controlled trials (RCTs) for new AUD therapies can be hampered by ineffective recruitment, leading to increased trial costs. The current analyses examined the effectiveness of recruitment efforts during two consecutive outpatient RCTs of novel AUD pharmacotherapies conducted between 2009 and 2012. Methods During an initial phone screen, participants identified an ad source for learning about the study. Qualified persons were then scheduled for in-person screens. The present analyses examined demographic differences amongst the eight ad sources utilized. Recruitment effectiveness was determined by dividing the number of persons meeting criteria for an in-person screen by the total number of callers from each ad source. Cost-effectiveness was determined by dividing total ad source cost by number of screens, participants randomized, and completers. Results 1,813 calls resulted in 1,005 completed phone screens. The most common ad source was TV (34%), followed by print (29%), word-of-mouth (11%), flyer (8%), internet (5%), radio (5%), bus ad (2%), and billboard (1%). Participants reporting bus ads (46%), billboard (44%), or print ads (34%) were significantly more likely than the other sources to meet criteria to be scheduled for in-person screens. The most cost-effective ad source was print ($2,506 per completer), while bus ad was the least cost-effective ($13,376 per completer). Conclusions Recruitment in AUD RCTs can be successful using diverse advertising methods. The present analyses favored use of print ads as most cost-effective. PMID:26752979

3D printing of modified-release aminosalicylate (4-ASA and 5-ASA) tablets.

PubMed

Goyanes, Alvaro; Buanz, Asma B M; Hatton, Grace B; Gaisford, Simon; Basit, Abdul W

2015-01-01

The aim of this study was to explore the potential of fused-deposition 3-dimensional printing (FDM 3DP) to produce modified-release drug loaded tablets. Two aminosalicylate isomers used in the treatment of inflammatory bowel disease (IBD), 5-aminosalicylic acid (5-ASA, mesalazine) and 4-aminosalicylic acid (4-ASA), were selected as model drugs. Commercially produced polyvinyl alcohol (PVA) filaments were loaded with the drugs in an ethanolic drug solution. A final drug-loading of 0.06% w/w and 0.25% w/w was achieved for the 5-ASA and 4-ASA strands, respectively. 10.5mm diameter tablets of both PVA/4-ASA and PVA/5-ASA were subsequently printed using an FDM 3D printer, and varying the weight and densities of the printed tablets was achieved by selecting the infill percentage in the printer software. The tablets were mechanically strong, and the FDM 3D printing was shown to be an effective process for the manufacture of the drug, 5-ASA. Significant thermal degradation of the active 4-ASA (50%) occurred during printing, however, indicating that the method may not be appropriate for drugs when printing at high temperatures exceeding those of the degradation point. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) of the formulated blends confirmed these findings while highlighting the potential of thermal analytical techniques to anticipate drug degradation issues in the 3D printing process. The results of the dissolution tests conducted in modified Hank's bicarbonate buffer showed that release profiles for both drugs were dependent on both the drug itself and on the infill percentage of the tablet. Our work here demonstrates the potential role of FDM 3DP as an efficient and low-cost alternative method of manufacturing individually tailored oral drug dosage, and also for production of modified-release formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

An instrument-free, screen-printed paper microfluidic device that enables bio and chemical sensing.

PubMed

Mohammadi, Saeed; Maeki, Masatoshi; Mohamadi, Reza M; Ishida, Akihiko; Tani, Hirofumi; Tokeshi, Manabu

2015-10-07

This paper describes a simple and instrument-free screen-printing method to fabricate hydrophilic channels by patterning polydimethylsiloxane (PDMS) onto chromatography paper. Clearly recognizable border lines were formed between hydrophilic and hydrophobic areas. The minimum width of the printed channel to deliver an aqueous sample was 600 μm, as obtained by this method. Fabricated microfluidic paper-based analytical devices (μPADs) were tested for several colorimetric assays of pH, glucose, and protein in both buffer and artificial urine samples and results were obtained in less than 30 min. The limits of detection (LODs) for glucose and bovine serum albumin (BSA) were 5 mM and 8 μM, respectively. Furthermore, the pH values of different solutions were visually recognised with the naked eye by using a sensitive ink. Ultimately, it is expected that this PDMS-screen-printing (PSP) methodology for μPADs can be readily translated to other colorimetric detection and hydrophilic channels surrounded by a hydrophobic polymer can be formed to transport fluids toward target zones.

Real-Time Monitoring of Cellular Bioenergetics with a Multi-Analyte Screen-Printed Electrode

PubMed Central

McKenzie, Jennifer R.; Cognata, Andrew C.; Davis, Anna N.; Wikswo, John P.; Cliffel, David E.

2016-01-01

Real-time monitoring of changes to cellular bioenergetics can provide new insights into mechanisms of action for disease and toxicity. This work describes the development of a multi-analyte screen-printed electrode for the detection of analytes central to cellular bioenergetics: glucose, lactate, oxygen, and pH. Platinum screen-printed electrodes were designed in-house and printed by Pine Research Instrumentation. Electrochemical plating techniques were used to form quasi-reference and pH electrodes. A Dimatix materials inkjet printer was used to deposit enzyme and polymer films to form sensors for glucose, lactate, and oxygen. These sensors were evaluated in bulk solution and microfluidic environments, and found to behave reproducibly and possess a lifetime of up to six weeks. Linear ranges and limits of detection for enzyme-based sensors were found to have an inverse relationship with enzyme loading, and iridium oxide pH sensors were found to have super-Nernstian responses. Preliminary measurements where the sensor was enclosed within a microfluidic channel with RAW 264.7 macrophages were performed to demonstrate the sensors’ capabilities for performing real-time microphysiometry measurements. PMID:26125545

Fabrication and Characterization of Flexible and Miniaturized Humidity Sensors Using Screen-Printed TiO2 Nanoparticles as Sensitive Layer

PubMed Central

Dubourg, Georges; Segkos, Apostolos; Katona, Jaroslav; Radović, Marko; Savić, Slavica; Crnojević-Bengin, Vesna

2017-01-01

This paper describes the fabrication and the characterization of an original example of a miniaturized resistive-type humidity sensor, printed on flexible substrate in a large-scale manner. The fabrication process involves laser ablation for the design of interdigitated electrodes on PET (Poly-Ethylene Terephthalate) substrate and a screen-printing process for the deposition of the sensitive material, which is based on TiO2 nanoparticles. The laser ablation process was carefully optimized to obtain micro-scale and well-resolved electrodes on PET substrate. A functional paste based on cellulose was prepared in order to allow the precise screen-printing of the TiO2 nanoparticles as sensing material on the top of the electrodes. The current against voltage (I–V) characteristic of the sensor showed good linearity and potential for low-power operation. The results of a humidity-sensing investigation and mechanical testing showed that the fabricated miniaturized sensors have excellent mechanical stability, sensing characteristics, good repeatability, and relatively fast response/recovery times operating at room temperature. PMID:28800063

A comparison of web-based versus print-based decision AIDS for prostate cancer screening: participants' evaluation and utilization.

PubMed

Tomko, Catherine; Davis, Kimberly M; Luta, George; Krist, Alexander H; Woolf, Steven H; Taylor, Kathryn L

2015-01-01

Patient decision aids facilitate informed decision making for medical tests and procedures that have uncertain benefits. To describe participants' evaluation and utilization of print-based and web-based prostate cancer screening decision aids that were found to improve decisional outcomes in a prior randomized controlled trial. Men completed brief telephone interviews at baseline, one month, and 13 months post-randomization. Participants were primary care patients, 45-70 years old, who received the print-based (N = 628) or web-based decision aid (N = 625) and completed the follow-up assessments. We assessed men's baseline preference for web-based or print-based materials, time spent using the decision aids, comprehension of the overall message, and ratings of the content. Decision aid use was self-reported by 64.3 % (web) and 81.8 % (print) of participants. Significant predictors of decision aid use were race (white vs. non-white, OR = 2.43, 95 % CI: 1.77, 3.35), higher education (OR = 1.68, 95 % CI: 1.06, 2.70) and trial arm (print vs. web, OR = 2.78, 95 % CI: 2.03, 3.83). Multivariable analyses indicated that web-arm participants were more likely to use the website when they preferred web-based materials (OR: 1.91, CI: 1.17, 3.12), whereas use of the print materials was not significantly impacted by a preference for print-based materials (OR: 0.69, CI: 0.38, 1.25). Comprehension of the decision aid message (i.e., screening is an individual decision) did not significantly differ between arms in adjusted analyses (print: 61.9 % and web: 68.2 %, p = 0.42). Decision aid use was independently influenced by race, education, and the decision aid medium, findings consistent with the 'digital divide.' These results suggest that when it is not possible to provide this age cohort with their preferred decision aid medium, print materials will be more highly used than web-based materials. Although there are many advantages to web-based decision aids, providing an option for print-based decision aids should be considered.

Acoustic and hybrid 3D-printed electrochemical biosensors for the real-time immunodetection of liver cancer cells (HepG2).

PubMed

Damiati, Samar; Küpcü, Seta; Peacock, Martin; Eilenberger, Christoph; Zamzami, Mazin; Qadri, Ishtiaq; Choudhry, Hani; Sleytr, Uwe B; Schuster, Bernhard

2017-08-15

This study presents an efficient acoustic and hybrid three-dimensional (3D)-printed electrochemical biosensors for the detection of liver cancer cells. The biosensors function by recognizing the highly expressed tumor marker CD133, which is located on the surface of liver cancer cells. Detection was achieved by recrystallizing a recombinant S-layer fusion protein (rSbpA/ZZ) on the surface of the sensors. The fused ZZ-domain enables immobilization of the anti-CD133 antibody in a defined manner. These highly accessible anti-CD133 antibodies were employed as a sensing layer, thereby enabling the efficient detection of liver cancer cells (HepG2). The recognition of HepG2 cells was investigated in situ using a quartz crystal microbalance with dissipation monitoring (QCM-D), which enabled the label-free, real-time detection of living cells on the modified sensor surface under controlled conditions. Furthermore, the hybrid 3D additive printing strategy for biosensors facilitates both rapid development and small-scale manufacturing. The hybrid strategy of combining 3D-printed parts and more traditionally fabricated parts enables the use of optimal materials: a ceramic substrate with noble metals for the sensing element and 3D-printed capillary channels to guide and constrain the clinical sample. Cyclic voltammetry (CV) measurements confirmed the efficiency of the fabricated sensors. Most importantly, these sensors offer low-cost and disposable detection platforms for real-world applications. Thus, as demonstrated in this study, both fabricated acoustic and electrochemical sensing platforms can detect cancer cells and therefore may have further potential in other clinical applications and drug-screening studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Nanocomposite thermite ink

DOEpatents

Tappan, Alexander S [Albuquerque, NM; Cesarano, III, Joseph; Stuecker, John N [Albuquerque, NM

2011-11-01

A nanocomposite thermite ink for use in inkjet, screen, and gravure printing. Embodiments of this invention do not require separation of the fuel and oxidizer constituents prior to application of the ink to the printed substrate.

Current Trends on Medical and Pharmaceutical Applications of Inkjet Printing Technology.

PubMed

Scoutaris, Nicolaos; Ross, Steven; Douroumis, Dennis

2016-08-01

Inkjet printing is an attractive material deposition and patterning technology that has received significant attention in the recent years. It has been exploited for novel applications including high throughput screening, pharmaceutical formulations, medical devices and implants. Moreover, inkjet printing has been implemented in cutting-edge 3D-printing healthcare areas such as tissue engineering and regenerative medicine. Recent inkjet advances enabled 3D printing of artificial cartilage and skin, or cell constructs for transplantation therapies. In the coming years inkjet printing is anticipated to revolutionize personalized medicine and push the innovation portfolio by offering new paths in patient - specific treatments.

Synthesis and characterization of high-T(sub c) screen-printed Y-Ba-Cu-O films on alumina

NASA Technical Reports Server (NTRS)

Bansal, Narottam P.; Simons, Rainee N.; Farrell, D. E.

1988-01-01

Thick films of YBa2Cu3O(sub 7-x) have been deposited on highly polished alumina substrates by the screen printing technique. To optimize the post-printing heat treatment, the films were baked at various temperatures for different lengths of time and oxygen-annealed at a lower temperature. The resulting films were characterized by electrical resistivity measurements, x-ray diffraction, and optical and scanning electron microscopy. Properties of the films were found to be highly sensitive to the post-printing thermal treatment. Films baked for 15 min at 1000 C in oxygen were hard, adherent, near single phase, and superconducting with T(sub c)(onset) approx 96 K, T(sub c)(zero) approx 66 K and Delta T sub c (10 to 90 percent) approx 10 K.

Screen printed passive components for flexible power electronics

NASA Astrophysics Data System (ADS)

Ostfeld, Aminy E.; Deckman, Igal; Gaikwad, Abhinav M.; Lochner, Claire M.; Arias, Ana C.

2015-10-01

Additive and low-temperature printing processes enable the integration of diverse electronic devices, both power-supplying and power-consuming, on flexible substrates at low cost. Production of a complete electronic system from these devices, however, often requires power electronics to convert between the various operating voltages of the devices. Passive components—inductors, capacitors, and resistors—perform functions such as filtering, short-term energy storage, and voltage measurement, which are vital in power electronics and many other applications. In this paper, we present screen-printed inductors, capacitors, resistors and an RLC circuit on flexible plastic substrates, and report on the design process for minimization of inductor series resistance that enables their use in power electronics. Printed inductors and resistors are then incorporated into a step-up voltage regulator circuit. Organic light-emitting diodes and a flexible lithium ion battery are fabricated and the voltage regulator is used to power the diodes from the battery, demonstrating the potential of printed passive components to replace conventional surface-mount components in a DC-DC converter application.

Screen printed passive components for flexible power electronics

PubMed Central

Ostfeld, Aminy E.; Deckman, Igal; Gaikwad, Abhinav M.; Lochner, Claire M.; Arias, Ana C.

2015-01-01

Additive and low-temperature printing processes enable the integration of diverse electronic devices, both power-supplying and power-consuming, on flexible substrates at low cost. Production of a complete electronic system from these devices, however, often requires power electronics to convert between the various operating voltages of the devices. Passive components—inductors, capacitors, and resistors—perform functions such as filtering, short-term energy storage, and voltage measurement, which are vital in power electronics and many other applications. In this paper, we present screen-printed inductors, capacitors, resistors and an RLC circuit on flexible plastic substrates, and report on the design process for minimization of inductor series resistance that enables their use in power electronics. Printed inductors and resistors are then incorporated into a step-up voltage regulator circuit. Organic light-emitting diodes and a flexible lithium ion battery are fabricated and the voltage regulator is used to power the diodes from the battery, demonstrating the potential of printed passive components to replace conventional surface-mount components in a DC-DC converter application. PMID:26514331

Screen printed passive components for flexible power electronics.

PubMed

Ostfeld, Aminy E; Deckman, Igal; Gaikwad, Abhinav M; Lochner, Claire M; Arias, Ana C

2015-10-30

Additive and low-temperature printing processes enable the integration of diverse electronic devices, both power-supplying and power-consuming, on flexible substrates at low cost. Production of a complete electronic system from these devices, however, often requires power electronics to convert between the various operating voltages of the devices. Passive components-inductors, capacitors, and resistors-perform functions such as filtering, short-term energy storage, and voltage measurement, which are vital in power electronics and many other applications. In this paper, we present screen-printed inductors, capacitors, resistors and an RLC circuit on flexible plastic substrates, and report on the design process for minimization of inductor series resistance that enables their use in power electronics. Printed inductors and resistors are then incorporated into a step-up voltage regulator circuit. Organic light-emitting diodes and a flexible lithium ion battery are fabricated and the voltage regulator is used to power the diodes from the battery, demonstrating the potential of printed passive components to replace conventional surface-mount components in a DC-DC converter application.

Bienzymatic Biosensor for Rapid Detection of Aspartame by Flow Injection Analysis

PubMed Central

Radulescu, Maria-Cristina; Bucur, Bogdan; Bucur, Madalina-Petruta; Radu, Gabriel Lucian

2014-01-01

A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h−1 with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 μM for methanol and 0.2 μM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement. PMID:24412899

Bienzymatic biosensor for rapid detection of aspartame by flow injection analysis.

PubMed

Radulescu, Maria-Cristina; Bucur, Bogdan; Bucur, Madalina-Petruta; Radu, Gabriel Lucian

2014-01-09

A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h⁻¹ with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 µM for methanol and 0.2 µM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement.

Cost-Effective Fabrication of Wettability Gradient Copper Surface by Screen Printing and its Application to Condensation Heat Transfer

NASA Astrophysics Data System (ADS)

Leu, Tzong-Shyng; Huang, Hung-Ming; Huang, Ding-Jun

2016-06-01

In this paper, wettability gradient pattern is applied to condensation heat transfer on a copper tube surface. For this application, the vital issue is how to fabricate gradient patterns on a curve tube surface to accelerate the droplet collection efficiently. For this purpose, novel fabrication processes are developed to form wettability gradient patterns on a curve copper tube surface by using roller screen printing surface modification techniques. The roller screen printing surface modification techniques can easily realize wettability gradient surfaces with superhydrophobicity and superhydrophilicity on a copper tube surface. Experimental results show the droplet nucleation sites, movement and coalescence toward the collection areas can be effectively controlled which can assist in removing the condensation water from the surface. The effectiveness of droplet collection is appropriate for being applied to condensation heat transfer in the foreseeable future.

Packaging strategy for maximizing the performance of a screen printed piezoelectric energy harvester

NASA Astrophysics Data System (ADS)

Zhang, Z.; Zhu, D.; Tudor, M. J.; Beeby, S. P.

2013-12-01

This paper reports the extended design and simulation of a screen printed piezoelectric energy harvester. The proposed design was based on a previous credit card sized smart tag sensor node, and packages the power conditioning circuit in the free space above the tungsten proof mass layer. This approach enables electronic components to be mounted onto the cantilever beam, which provides additional weight at the tip of the cantilever structure. The design structure contains a T-shape cantilever beam with size of 47 mm × 30 mm × 0.85 mm which is fabricated using screen printing. ANSYS simulation results predict the revised architecture can generate 421.9 μW approximately twice of the RMS power produced by the original design along with a higher open-circuit RMS Voltage of 8.0 V while the resonant frequency is dropped to 53.4 Hz.

How Are My Newborn's Screening Results Used?

MedlinePlus

... Pinterest Email Print How are my newborn’s screening results used? In most cases, parents don't hear ... for a particular condition(s). 1 Out of Range Results If the screening detects one or more conditions, ...

[Leaflets and websites on colorectal cancer screening and their quality assessment from experts' views].

PubMed

Dreier, M; Borutta, B; Seidel, G; Münch, I; Töppich, J; Bitzer, E-M; Dierks, M-L; Walter, U

2014-03-01

In Germany, individuals who have statutory health insurance have free access to colorectal cancer (CRC) screening tests, and can choose between a fecal occult blood test and a screening colonoscopy. Evidence-based health information may support informed choices regarding whether or not to undergo CRC screening. The aim of this study was to assess whether the available German information materials on CRC screening meet evidence-based health information standards. A systematic search was made for print media and websites on CRC screening addressed to German people with average CRC risk (search period for print media August 2010, for websites January-March 2012). The identified information was assessed with a newly developed comprehensive list of criteria. In all, 41 print media, including 28 flyers and 13 brochures, and 36 websites were identified and assessed. These materials reported more often the benefits than the risks of CRC screening, and quantified presentations of benefits and risks were less frequently given. Most of the materials called for participation and did not indicate the option to decide whether or not to attend CRC screening. This bias in favor of screening was increased by fear-provoking or downplayed wording. Most materials included false and misleading information. The requirements for evidence-based patient information were currently not met by most of the leaflets and websites in Germany. Feedback was given to the producers of the leaflets including a discussion of the findings. The results may be used to revise existing leaflets or to develop new health information on CRC screening.

Can a print-based intervention increase screening for first degree relatives of people with colorectal cancer? A randomised controlled trial.

PubMed

Carey, Mariko; Sanson-Fisher, Robert; Macrae, Finlay; Cameron, Emilie; Hill, David; D'Este, Catherine; Simmons, Jody; Doran, Christopher

2016-12-01

To test the effectiveness of a targeted print-based intervention to improve screening adherence in first degree relatives of people with colorectal cancer (CRC). People with CRC and their adult first degree relatives were identified through a population-based cancer registry and randomly allocated as a family unit to the intervention or control condition. The control group received general information about CRC screening. The intervention group received printed advice regarding screening that was targeted to their risk level. Screening adherence was assessed at baseline and at 12 months via self report. 752 (25%) index cases and 574 (34%) eligible first degree relatives consented to take part in the trial and completed baseline interviews. At 12 months, 58% of first degree relatives in the control group and 61% in the intervention group were adherent to screening guidelines (mixed effects logistic regression group by time interaction effect =2.7; 95%CI=1.2-5.9; P=0.013). Subgroup analysis indicated that the intervention was only effective for those with the lowest risk. Provision of personalised risk information may have a modest effect on adherence to CRC screening recommendations among first degree relatives of people diagnosed with CRC. Improved strategies for identifying and engaging first degree relatives are needed to maximise the population impact of the intervention. © 2016 The Authors.

Graphene-loaded nanofiber-modified electrodes for the ultrasensitive determination of dopamine.

PubMed

Rodthongkum, Nadnudda; Ruecha, Nipapan; Rangkupan, Ratthapol; Vachet, Richard W; Chailapakul, Orawon

2013-12-04

A novel and highly sensitive electrochemical system based on electrospun graphene/polyaniline/polystyrene (G/PANI/PS) nanofiber-modified screen-printed carbon electrodes has been developed for dopamine (DA) determination. A dramatic increase (9 times) in the current signal for the redox reaction of a standard, ferri/ferrocyanide [Fe(CN)6](3-/4-) couple was found when compared to an unmodified electrode. This modified electrode also exhibited favorable electron transfer kinetics and excellent electrocatalytic activity toward the oxidation of DA. When used together with square wave voltammetry (SWV), DA can be selectively determined in the presence of the common interferents (i.e. ascorbic acid and uric acid). Under optimal conditions, a very low limit of detection (0.05 nM) and limit of quantification (0.30 nM) were achieved for DA. In addition, a wide dynamic range of 0.1 nM to 100 μM was found for this electrode system. Finally, the system can be successfully applied to determine DA in complex biological environment (e.g. human serum, urine) with excellent reproducibility. Copyright © 2013 Elsevier B.V. All rights reserved.

Preparation of β-cyclodextrin entrapped graphite composite for sensitive detection of dopamine.

PubMed

Palanisamy, Selvakumar; Sakthinathan, S; Chen, Shen-Ming; Thirumalraj, Balamurugan; Wu, Tsung-Han; Lou, Bih-Show; Liu, Xiaoheng

2016-01-01

A simple dopamine (DA) electrochemical sensor was developed based on a screen-printed carbon electrode (SPCE) modified with β-cyclodextrin entrapped graphite (GR/β-CD) composite for the first time. The polar hydroxyl groups on the β-CD rims interact with polar groups of edges of GR sheets resulting into the high dispersion ability of GR in β-CD solution. The GR/β-CD modified electrode exhibited a higher electrochemical response to DA with a lower oxidation potential (0.224V) than that of bare/β-CD (0.38V) and GR (0.525V) modified SPCEs, revealing an excellent electro-oxidation behavior of GR/β-CD composite toward DA. Under optimum conditions, the fabricated sensor detects the DA in the linear concentration range from 0.1 to 58.5μM with a limit of detection of 0.011μM and the sensitivity of 1.27±0.02μAμM(-1)cm(-2). The fabricated sensor also exhibits the excellent repeatability, practicality, reproducibility, storage stability along with acceptable selectivity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Monolithic quasi-solid-state dye-sensitized solar cells based on graphene modified mesoscopic carbon counter electrodes

NASA Astrophysics Data System (ADS)

Rong, Yaoguang; Li, Xiong; Liu, Guanghui; Wang, Heng; Ku, Zhiliang; Xu, Mi; Liu, Linfeng; Hu, Min; Yang, Ying; Han, Hongwei

2013-03-01

We have developed a monolithic quasi-solid-state dye-sensitized solar cell (DSSC) based on graphene modified mesoscopic carbon counter electrode (GC-CE), which offers a promising prospect for commercial applications. Based on the design of a triple layer structure, the TiO2 working electrode layer, ZrO2 spacer layer and carbon counter electrode (CE) layer are constructed on a single conducting glass substrate by screen-printing. The quasi-solid-state polymer gel electrolyte employs a polymer composite as the gelator and could effectively infiltrate into the porous layers. Fabricated with normal carbon counter electrode (NC-CE) containing graphite and carbon black, the device shows a power conversion efficiency (PCE) of 5.09% with the fill factor (FF) of 0.63 at 100 mW cm-2 AM1.5 illumination. When the NC-CE is modified with graphene sheets, the PCE and FF could be enhanced to 6.27% and 0.71, respectively. This improvement indicates excellent conductivity and high electrocatalytic activity of the graphene sheets, which have been considered as a promising platinum-free electrode material for DSSCs.

Highly Sensitive and Selective Hydrogen Gas Sensor Using the Mesoporous SnO₂ Modified Layers.

PubMed

Xue, Niuzi; Zhang, Qinyi; Zhang, Shunping; Zong, Pan; Yang, Feng

2017-10-14

It is important to improve the sensitivities and selectivities of metal oxide semiconductor (MOS) gas sensors when they are used to monitor the state of hydrogen in aerospace industry and electronic field. In this paper, the ordered mesoporous SnO₂ (m-SnO₂) powders were prepared by sol-gel method, and the morphology and structure were characterized by X-ray diffraction analysis (XRD), transmission electron microscope (TEM) and Brunauer-Emmett-Teller (BET). The gas sensors were fabricated using m-SnO₂ as the modified layers on the surface of commercial SnO₂ (c-SnO₂) by screen printing technology, and tested for gas sensing towards ethanol, benzene and hydrogen with operating temperatures ranging from 200 °C to 400 °C. Higher sensitivity was achieved by using the modified m-SnO₂ layers on the c-SnO₂ gas sensor, and it was found that the S(c/m2) sensor exhibited the highest response (Ra/Rg = 22.2) to 1000 ppm hydrogen at 400 °C. In this paper, the mechanism of the sensitivity and selectivity improvement of the gas sensors is also discussed.

Print news coverage of cancer: what prevention messages are conveyed when screening is newsworthy?

PubMed

Smith, Katherine Clegg; Kromm, Elizabeth Edsall; Klassen, Ann Carroll

2010-08-01

Americans are generally favorable towards cancer screening, but fatalistic about cancer prevention. News coverage shapes perceptions of cancer control in meaningful ways, but there is little consensus as to the impact of news on our understanding of and engagement in cancer screening practices. Our analysis of cancer screening-related print news coverage during a four month period in 2005 suggests that the newsworthiness of new screening technologies may undermine public confidence in currently available and effective secondary prevention programs, while promoting tests whose effectiveness is debated or not yet established. We conducted a structured text analysis of 517 cancer-related news articles from 15 leading daily newspapers and a subsequent qualitative analysis of the 79 screening news articles. Screening articles were analyzed for content related to criteria for screening effectiveness. Content patterns for each type of screening and cancer were also noted. News coverage consistently conveyed screening as important and highlighted the need to protect and expand access to screening. At the same time, to the extent that story content was framed by the newsworthiness of new tests and technologies this often indirectly called into question effective and established protocols and programs without providing any actionable alternative. This analysis revealed unexpected messages about screening that are potentially problematic for cancer control. The cancer control community should continue efforts to understand and shape news coverage of screening in order to promote balanced and action-oriented content. Research has shown that Americans hold conflicting views regarding cancer-having a favorable opinion of screening while simultaneously feeling fatalistic about prevention. Our analysis of print news stories on cancer screening suggests that the determination of screening's "newsworthiness" is related to newly developed tests and protocols, which may create demand for new tests whose effectiveness is unknown and undermine confidence in established and effective screening programs.

Filling schemes of silver dots inkjet-printed on pixelated nanostructured surfaces

NASA Astrophysics Data System (ADS)

Alan, Sheida; Jiang, Hao; Shahbazbegian, Haleh; Patel, Jasbir N.; Kaminska, Bozena

2017-03-01

Recently, our group demonstrated an inkjet-based technique to enable high-throughput, versatile and full-colour printing of structural colours on generic pixelated nanostructures, termed as molded ink on nanostructured surfaces. The printed colours are controlled by the area of printed silver on the pixelated red, green and blue polymer nanostructure arrays. This paper investigates the behaviour of jetted silver ink droplets on nanostructured surfaces and the microscale dot patterns implemented during printing process, for achieving accurate and consistent colours in the printed images. The surface wettability and the schemes of filling silver dots inside the subpixels are crucial to the quality of printed images. Several related concepts and definitions are introduced, such as filling ratio, full dots per subpixel (DPSP), number of printable colours, colour leaking and dot merging. In our experiments, we first chemically modified the surface to control the wettability and dot size. From each type of modified surface, various filling schemes were experimented and the printed results were evaluated with comprehensive considerations on the number of printable colours and the negative effects of colour leaking and dot merging. Rational selection of the best filling scheme resulted in a 2-line filling scheme using 20 μm dot spacing and line spacing capable of printing 9261 different colours with 121 pixel per inch display resolution, on low-wettability surface. This study is of vital importance for scaling up the printing technique in industrial applications and provides meaningful insights for inkjet-printing on nanostructures.

Determination of mercury in ambient water samples by anodic stripping voltammetry on screen-printed gold electrodes.

PubMed

Bernalte, E; Marín Sánchez, C; Pinilla Gil, E

2011-03-09

The applicability of commercial screen-printed gold electrodes (SPGEs) for the determination of Hg(II) in ambient water samples by square wave anodic stripping voltammetry has been demonstrated. Electrode conditioning procedures, chemical and instrumental variables have been optimized to develop a reliable method capable of measuring dissolved mercury in the low ng mL(-1) range (detection limit 1.1 ng mL(-1)), useful for pollution monitoring or screening purposes. The proposed method was tested with the NIST 1641d Mercury in Water Standard Reference Material (recoveries 90.0-110%) and the NCS ZC 76303 Mercury in Water Certified Reference Material (recoveries 82.5-90.6%). Waste water samples from industrial origin and fortified rain water samples were assayed for mercury by the proposed method and by a reference ICP-MS method, with good agreement. Screen printing technology thus opens a useful way for the construction of reliable electrochemical sensors for decentralized or even field Hg(II) testing. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of sintering temperatures and screen printing types on TiO2 layers in DSSC applications

NASA Astrophysics Data System (ADS)

Supriyanto, Agus; Furqoni, Lutfi; Nurosyid, Fahru; Hidayat, Jojo; Suryana, Risa

2016-03-01

Dye-Sensitized Solar Cell (DSSC) is a candidate solar cell, which has a big potential in the future due to its eco-friendly material. This research is conducted to study the effect of sintering temperature and the type of screen-printing toward the characteristics of TiO2 layer as a working electrode in DSSC. TiO2 layers were fabricated using a screen-printing method with a mesh size of T-49, T-55, and T-61. TiO2 layers were sintered at temperatures of 600°C and 650°C for 60 min. DSSC structure was composed of TiO2 as semiconductors, ruthenium complex as dyes, and carbon as counter electrodes. The morphology of TiO2 layer was observed by using Nikon E2 Digital Camera Microscopy. The efficiencies of DSSC were calculated from the I-V curves. The highest efficiency is 0.015% at TiO2 layer fabricated with screen type T-61 and at a sintering temperature of 650°C.

Pulsed Polarization-Based NOx Sensors of YSZ Films Produced by the Aerosol Deposition Method and by Screen-Printing

PubMed Central

Exner, Jörg; Albrecht, Gaby; Schönauer-Kamin, Daniela; Kita, Jaroslaw; Moos, Ralf

2017-01-01

The pulsed polarization technique on solid electrolytes is based on alternating potential pulses interrupted by self-discharge pauses. Since even small concentrations of nitrogen oxides (NOx) in the ppm range significantly change the polarization and discharge behavior, pulsed polarization sensors are well suited to measure low amounts of NOx. In contrast to all previous investigations, planar pulsed polarization sensors were built using an electrolyte thick film and platinum interdigital electrodes on alumina substrates. Two different sensor layouts were investigated, the first with buried Pt electrodes under the electrolyte and the second one with conventional overlying Pt electrodes. Electrolyte thick films were either formed by aerosol deposition or by screen-printing, therefore exhibiting a dense or porous microstructure, respectively. For screen-printed electrolytes, the influence of the electrolyte resistance on the NOx sensing ability was investigated as well. Sensors with buried electrodes showed little to no response even at higher NOx concentrations, in good agreement with the intended sensor mechanism. Electrolyte films with overlying electrodes, however, allowed the quantitative detection of NOx. In particular, aerosol deposited electrolytes exhibited high sensitivities with a sensor output signal ΔU of 50 mV and 75 mV for 3 ppm of NO and NO2, respectively. For screen-printed electrolytes, a clear trend indicated a decrease in sensitivity with increased electrolyte resistance. PMID:28933736

Cathode material for lithium ion accumulators prepared by screen printing for Smart Textile applications

NASA Astrophysics Data System (ADS)

Syrový, T.; Kazda, T.; Syrová, L.; Vondrák, J.; Kubáč, L.; Sedlaříková, M.

2016-03-01

The presented study is focused on the development of LiFePO4 based cathode for thin and flexible screen printed secondary lithium based accumulators. An ink formulation was developed for the screen printing technique, which enabled mass production of accumulator's cathode for Smart Label and Smart Textile applications. The screen printed cathode was compared with an electrode prepared by the bar coating technique using an ink formulation based on the standard approach of ink composition. Obtained LiFePO4 cathode layers were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and galvanostatic charge/discharge measurements at different loads. The discharge capacity, capacity retention and stability at a high C rate of the LiFePO4 cathode were improved when Super P and PVDF were replaced by conductive polymers PEDOT:PSS. The achieved capacity during cycling at various C rates was approximately the same at the beginning and at the end, and it was about 151 mAh/g for cycling under 1C. The obtained results of this novelty electrode layer exceed the parameters of several electrode layers based on LiFePO4 published in literature in terms of capacity, cycling stability and overcomes them in terms of simplicity/industrial process ability of cathode layer fabrication and electrode material preparation.

Pulsed Polarization-Based NOx Sensors of YSZ Films Produced by the Aerosol Deposition Method and by Screen-Printing.

PubMed

Exner, Jörg; Albrecht, Gaby; Schönauer-Kamin, Daniela; Kita, Jaroslaw; Moos, Ralf

2017-07-26

The pulsed polarization technique on solid electrolytes is based on alternating potential pulses interrupted by self-discharge pauses. Since even small concentrations of nitrogen oxides (NO x ) in the ppm range significantly change the polarization and discharge behavior, pulsed polarization sensors are well suited to measure low amounts of NO x . In contrast to all previous investigations, planar pulsed polarization sensors were built using an electrolyte thick film and platinum interdigital electrodes on alumina substrates. Two different sensor layouts were investigated, the first with buried Pt electrodes under the electrolyte and the second one with conventional overlying Pt electrodes. Electrolyte thick films were either formed by aerosol deposition or by screen-printing, therefore exhibiting a dense or porous microstructure, respectively. For screen-printed electrolytes, the influence of the electrolyte resistance on the NO x sensing ability was investigated as well. Sensors with buried electrodes showed little to no response even at higher NO x concentrations, in good agreement with the intended sensor mechanism. Electrolyte films with overlying electrodes, however, allowed the quantitative detection of NO x . In particular, aerosol deposited electrolytes exhibited high sensitivities with a sensor output signal Δ U of 50 mV and 75 mV for 3 ppm of NO and NO₂, respectively. For screen-printed electrolytes, a clear trend indicated a decrease in sensitivity with increased electrolyte resistance.

Identification of Novel "Inks" for 3D Printing Using High-Throughput Screening: Bioresorbable Photocurable Polymers for Controlled Drug Delivery.

PubMed

Louzao, Iria; Koch, Britta; Taresco, Vincenzo; Ruiz-Cantu, Laura; Irvine, Derek J; Roberts, Clive J; Tuck, Christopher; Alexander, Cameron; Hague, Richard; Wildman, Ricky; Alexander, Morgan R

2018-02-28

A robust methodology is presented to identify novel biomaterials suitable for three-dimensional (3D) printing. Currently, the application of additive manufacturing is limited by the availability of functional inks, especially in the area of biomaterials; this is the first time when this method is used to tackle this problem, allowing hundreds of formulations to be readily assessed. Several functional properties, including the release of an antidepressive drug (paroxetine), cytotoxicity, and printability, are screened for 253 new ink formulations in a high-throughput format as well as mechanical properties. The selected candidates with the desirable properties are successfully scaled up using 3D printing into a range of object architectures. A full drug release study and degradability and tensile modulus experiments are presented on a simple architecture to validating the suitability of this methodology to identify printable inks for 3D printing devices with bespoke properties.

Differences in perceived difficulty in print and online patient education materials.

PubMed

Farnsworth, Michael

2014-01-01

Written patient education materials frequently exceed the reading ability of the general public. Patients are often intimidated by the task of reading patient education materials, perceiving the materials’ difficulty levels as prohibitive, even when they do not exceed the patients’ reading abilities. It is unclear how the delivery mechanism--print or a computer screen--affects a patient’s reading experience through his/her perception of its difficulty. To determine whether first-year college students perceived online or print-based patient education materials as more difficult to read. Convenience sampling of first-year college students. Some first-year college students perceived online patient education materials to be more difficult to read than print-based ones--even when the reading level of the patient education materials was similar. Demographic information about this sample’s high levels of digital literacy suggests that other populations might also perceive online patient education materials as more difficult to read than print-based equivalents. Patients’ perceptions of the difficulty of patient education materials influenced their ability to effectively learn from those materials. This article concludes with a call for more research into patients’ perceptions of difficulty of patient education materials in print vs on a screen.

Using focus groups to develop interventions to promote colorectal cancer screening among Vietnamese Americans.

PubMed

Nguyen, Bang H; Vo, Phuong H; Doan, Hiep T; McPhee, Stephen J

2006-01-01

Colorectal cancer is the third most common cancer in Vietnamese Americans. Their colorectal screening rates are lower than the rates of whites. Four focus groups were conducted to identify Vietnamese American sources and credibility of health information, media utilization, and intervention approaches. Vietnamese Americans trusted doctors and patient testimonials and had access to, and received most of their health information from, Vietnamese- language print and electronic media. Recommended intervention approaches include promoting doctors' recommendation of screening and using Vietnamese-language mass media, print materials, and oral presentations. Focus groups are useful in determining communication channels and intervention approaches.

A High Precision $3.50 Open Source 3D Printed Rain Gauge Calibrator

NASA Astrophysics Data System (ADS)

Lopez Alcala, J. M.; Udell, C.; Selker, J. S.

2017-12-01

Currently available rain gauge calibrators tend to be designed for specific rain gauges, are expensive, employ low-precision water reservoirs, and do not offer the flexibility needed to test the ever more popular small-aperture rain gauges. The objective of this project was to develop and validate a freely downloadable, open-source, 3D printed rain gauge calibrator that can be adjusted for a wide range of gauges. The proposed calibrator provides for applying low, medium, and high intensity flow, and allows the user to modify the design to conform to unique system specifications based on parametric design, which may be modified and printed using CAD software. To overcome the fact that different 3D printers yield different print qualities, we devised a simple post-printing step that controlled critical dimensions to assure robust performance. Specifically, the three orifices of the calibrator are drilled to reach the three target flow rates. Laboratory tests showed that flow rates were consistent between prints, and between trials of each part, while the total applied water was precisely controlled by the use of a volumetric flask as the reservoir.

Ultra-Rapid 2-D and 3-D Laser Microprinting of Proteins

NASA Astrophysics Data System (ADS)

Scott, Mark Andrew

When viewed under the microscope, biological tissues reveal an exquisite microarchitecture. These complex patterns arise during development, as cells interact with a multitude of chemical and mechanical cues in the surrounding extracellular matrix. Tissue engineers have sought for decades to repair or replace damaged tissue, often relying on porous scaffolds as an artificial extracellular matrix to support cell development. However, these grafts are unable to recapitulate the complexity of the in vivo environment, limiting our ability to regenerate functional tissue. Biomedical engineers have developed several methods for printing two- and three-dimensional patterns of proteins for studying and directing cell development. Of these methods, laser microprinting of proteins has shown the most promise for printing sub-cellular resolution gradients of cues, but the photochemistry remains too slow to enable large-scale applications for screening and therapeutics In this work, we demonstrate a novel high-speed photochemistry based on multi-photon photobleaching of fluorescein, and we build the fastest 2-D and 3-D laser microprinter for proteins to date. First, we show that multiphoton photobleaching of a deoxygenated solution of biotin-4-fluorescein onto a PEG monolayer with acrylate end-group can enable print speeds of almost 20 million pixels per second at 600 nanometer resolution. We discovered that the mechanism of fluorescein photobleaching evolves from a 2-photon to 3- and 4-photon regime at higher laser intensities, unlocking faster printing kinetics. Using this 2-D printing system, we develop a novel triangle-ratchet method for directing the polarization of single hippocampal neurons. This ability to determine which neurite becomes an axon, and which neuritis become dendrites is an essential step for developing defined in vitro neural networks. Next, we modify our multiphoton photobleaching system to print in three dimensions. For the first time, we demonstrate 3-D printing of full length proteins in collagen, fibrin and gelatin methacrylate scaffolds, as well as printing in agarose and agarose methacrylate scaffolds. We also present a novel method for 3-D printing collagen scaffolds at unprecedented speeds, up to 14layers per second, generating complex shapes in seconds with sub-micron resolution. Finally, we demonstrate that 3-D printing of scaffold architecture and protein cues inside the scaffold can be combined, for the first time enabling structures with complex sub-micron architectures and chemical cues for directing development. We believe that the ultra-rapid printing technology presented in this thesis will be a key enabler in the development of complex, artificially engineered tissues and organs. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

Electrochemical lactate biosensor based upon chitosan/carbon nanotubes modified screen-printed graphite electrodes for the determination of lactate in embryonic cell cultures.

PubMed

Hernández-Ibáñez, Naiara; García-Cruz, Leticia; Montiel, Vicente; Foster, Christopher W; Banks, Craig E; Iniesta, Jesús

2016-03-15

l-lactate is an essential metabolite present in embryonic cell culture. Changes of this important metabolite during the growth of human embryo reflect the quality and viability of the embryo. In this study, we report a sensitive, stable, and easily manufactured electrochemical biosensor for the detection of lactate within embryonic cell cultures media. Screen-printed disposable electrodes are used as electrochemical sensing platforms for the miniaturization of the lactate biosensor. Chitosan/multi walled carbon nanotubes composite have been employed for the enzymatic immobilization of the lactate oxidase enzyme. This novel electrochemical lactate biosensor analytical efficacy is explored towards the sensing of lactate in model (buffer) solutions and is found to exhibit a linear response towards lactate over the concentration range of 30.4 and 243.9 µM in phosphate buffer solution, with a corresponding limit of detection (based on 3-sigma) of 22.6 µM and exhibits a sensitivity of 3417 ± 131 µAM(-1) according to the reproducibility study. These novel electrochemical lactate biosensors exhibit a high reproducibility, with a relative standard deviation of less than 3.8% and an enzymatic response over 82% after 5 months stored at 4 °C. Furthermore, high performance liquid chromatography technique has been utilized to independently validate the electrochemical lactate biosensor for the determination of lactate in a commercial embryonic cell culture medium providing excellent agreement between the two analytical protocols. Copyright © 2015 Elsevier B.V. All rights reserved.

Electrochemical Sensors Based on Screen-Printed Electrodes: The Use of Phthalocyanine Derivatives for Application in VFA Detection

PubMed Central

Ndiaye, Amadou L.; Delile, Sébastien; Brunet, Jérôme; Varenne, Christelle; Pauly, Alain

2016-01-01

Here, we report on the use of electrochemical methods for the detection of volatiles fatty acids (VFAs), namely acetic acid. We used tetra-tert-butyl phthalocyanine (PcH2-tBu) as the sensing material and investigated its electroanalytical properties by means of cyclic voltammetry (CV) and square wave voltammetry (SWV). To realize the electrochemical sensing system, the PcH2-tBu has been dropcast-deposited on carbon (C) orgold (Au)screen-printed electrodes (SPEs) and characterized by cyclic voltammetry and scanning electron microscopy (SEM). The SEM analysis reveals that the PcH2-tBu forms mainly aggregates on the SPEs. The modified electrodes are used for the detection of acetic acid and present a linear current increase when the acetic acid concentration increases. The Cmodified electrode presents a limit of detection (LOD) of 25.77 mM in the range of 100 mM–400 mM, while the Aumodified electrode presents an LOD averaging 40.89 mM in the range of 50 mM–300 mM. When the experiment is realized in a buffered condition, theCmodified electrode presents a lower LOD, which averagesthe 7.76 mM. A pronounced signal decay attributed to an electrode alteration is observed in the case of the gold electrode. This electrode alteration severely affects the coating stability. This alteration is less perceptible in the case of the carbon electrode. PMID:27598214

Graphitized carbon nanofiber-Pt nanoparticle hybrids as sensitive tool for preparation of screen printing biosensors. Detection of lactate in wines and ciders.

PubMed

Loaiza, Oscar A; Lamas-Ardisana, Pedro J; Añorga, Larraitz; Jubete, Elena; Ruiz, Virginia; Borghei, Maryam; Cabañero, Germán; Grande, Hans J

2015-02-01

This work describes the fabrication of a new lactate biosensor. The strategy is based on the use of a novel hybrid nanomaterial for amperometric biosensors i.e. platinum nanoparticles (PtNps) supported on graphitized carbon nanofibers (PtNps/GCNF) prepared by chemical reduction of the Pt precursor at GCNF surfaces. The biosensors were constructed by covalent immobilization of lactate oxidase (LOx) onto screen printed carbon electrodes (SPCEs) modified with PtNps (PtNps/GCNF-SPCEs) using polyethyleneimine (PEI) and glutaraldehyde (GA). Experimental variables concerning both the biosensor design and the detection process were investigated for an optimal analytical performance. Lactate biosensors show good reproducibility (RSD 4.9%, n=10) and sensitivity (41,302±546) μA/Mcm(2), with a good limit of detection (6.9μM). Covalent immobilization of the enzyme allows the reuse of the biosensor for several measurements, converting them in a cheap alternative to the solid electrodes. The long-term stability of the biosensors was also evaluated. 90% of the signal was kept after 3months of storage at room temperature (RT), while 95% was retained after 18months at -20°C. These results demonstrate that the method provides sensitive electrochemical lactate biosensors where the stability of the enzymatic activity can be preserved for a long period of time in adequate storage conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Rhodium nanoparticle-modified screen-printed graphite electrodes for the determination of hydrogen peroxide in tea extracts in the presence of oxygen.

PubMed

Gatselou, Vasiliki A; Giokas, Dimothenis L; Vlessidis, Athanasios G; Prodromidis, Mamas I

2015-03-01

In this work we describe the fabrication of nanostructured electrocatalytic surfaces based on polyethyleneimine (PEI)-supported rhodium nanoparticles (Rh-NP) over graphite screen-printed electrodes (SPEs) for the determination of hydrogen peroxide in the presence of oxygen. Rh-NP, electrostatically stabilized by citrate anions, were immobilized over graphite SPEs, through coulombic attraction on a thin film of positively charged PEI. The functionalized sensors, polarized at 0.0 V vs. Ag/AgCl/3 M KCl, exhibited a linear response to H2O2 over the concentration range from 5 to 600 μmol L(-1) H2O2 in the presence of oxygen. The 3σ limit of detection was 2 μmol L(-1) H2O2, while the reproducibility of the method at the concentration level of 10 μmol L(-1) H2O2 (n=10) and between different sensors (n=4) was lower than 3 and 5%, respectively. Most importantly, the sensors showed an excellent working and storage stability at ambient conditions and they were successfully applied to the determination of H2O2 produced by autooxidation of polylphenols in tea extracts with ageing. Recovery rates ranged between 97 and 104% suggesting that the as-prepared electrodes can be used for the development of small-scale, low-cost chemical sensors for use in on-site applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Bioinspired Multifunctional Superhydrophobic Surfaces with Carbon-Nanotube-Based Conducting Pastes by Facile and Scalable Printing.

PubMed

Han, Joong Tark; Kim, Byung Kuk; Woo, Jong Seok; Jang, Jeong In; Cho, Joon Young; Jeong, Hee Jin; Jeong, Seung Yol; Seo, Seon Hee; Lee, Geon-Woong

2017-03-01

Directly printed superhydrophobic surfaces containing conducting nanomaterials can be used for a wide range of applications in terms of nonwetting, anisotropic wetting, and electrical conductivity. Here, we demonstrated that direct-printable and flexible superhydrophobic surfaces were fabricated on flexible substrates via with an ultrafacile and scalable screen printing with carbon nanotube (CNT)-based conducting pastes. A polydimethylsiloxane (PDMS)-polyethylene glycol (PEG) copolymer was used as an additive for conducting pastes to realize the printability of the conducting paste as well as the hydrophobicity of the printed surface. The screen-printed conducting surfaces showed a high water contact angle (WCA) (>150°) and low contact angle hysteresis (WCA < 5°) at 25 wt % PDMS-PEG copolymer in the paste, and they have an electrical conductivity of over 1000 S m -1 . Patterned superhydrophobic surfaces also showed sticky superhydrophobic characteristics and were used to transport water droplets. Moreover, fabricated films on metal meshes were used for an oil/water separation filter, and liquid evaporation behavior was investigated on the superhydrophobic and conductive thin-film heaters by applying direct current voltage to the film.

Colorectal (Colon) Cancer: What Are the Risk Factors?

MedlinePlus

... for Life Campaign Print Materials Fact Sheet Brochures Posters Postcards Public Service Announcements Personal Screening Stories Campaign Research Poster Presentation: Why Should I Get Screened? Colorectal Cancer ...

Colorectal (Colon) Cancer: Questions to Ask Your Doctor

MedlinePlus

... for Life Campaign Print Materials Fact Sheet Brochures Posters Postcards Public Service Announcements Personal Screening Stories Campaign Research Poster Presentation: Why Should I Get Screened? Colorectal Cancer ...

Influence of the UV radiation on the screen-printed pH-sensitive layers based on graphene and ruthenium dioxide

NASA Astrophysics Data System (ADS)

Pepłowski, A.; Grudziński, D.; Raczyński, T.; Wróblewski, G.; Janczak, D.; Jakubowska, M.

2017-08-01

Electrodes for measuring pH of the solution were fabricated by the means of screen-printing technology. Potentiometric sensors' layers comprised of composite with polymer matrix and graphene nanoplatelets/ruthenium (IV) oxide nanopowder as functional phase. Transceivers were printed on the elastic PMMA foil. Regarding potential application of the sensors in the wearable devices, dynamic response of the electrodes to changing ultraviolet radiation levels was assessed, since RuO2 is reported to be UV-sensitive. Observed changes of the electrodes' potential were of sub-millivolt magnitude, being comparable to simultaneously observed signal drift. Given this stability under varying UV conditions and previously verified good flexibility, fabricated sensors meet the requirements for wearable applications.

Perfect Color Registration Realized.

ERIC Educational Resources Information Center

Lovedahl, Gerald G.

1979-01-01

Describes apparatus and procedures to design and construct a "printing box" as a graphic arts project to make color prints on T-shirts using photography, indirect and direct photo screen methods, and other types of stencils. Step-by-step photographs illustrate the process. (MF)

Capillary flow of amorphous metal for high performance electrode

PubMed Central

Kim, Se Yun; Kim, Suk Jun; Jee, Sang Soo; Park, Jin Man; Park, Keum Hwan; Park, Sung Chan; Cho, Eun Ae; Lee, Jun Ho; Song, In Yong; Lee, Sang Mock; Han, In Taek; Lim, Ka Ram; Kim, Won Tae; Park, Ju Cheol; Eckert, Jürgen; Kim, Do Hyang; Lee, Eun-Sung

2013-01-01

Metallic glass (MG) assists electrical contact of screen-printed silver electrodes and leads to comparable electrode performance to that of electroplated electrodes. For high electrode performance, MG needs to be infiltrated into nanometer-scale cavities between Ag particles and reacts with them. Here, we show that the MG in the supercooled state can fill the gap between Ag particles within a remarkably short time due to capillary effect. The flow behavior of the MG is revealed by computational fluid dynamics and density funtional theory simulation. Also, we suggest the formation mechanism of the Ag electrodes, and demonstrate the criteria of MG for higher electrode performance. Consequently, when Al85Ni5Y8Co2 MG is added in the Ag electrodes, cell efficiency is enhanced up to 20.30% which is the highest efficiency reported so far for screen-printed interdigitated back contact solar cells. These results show the possibility for the replacement of electroplating process to screen-printing process. PMID:23851671

Evaluation of electrochemical, UV/VIS and Raman spectroelectrochemical detection of Naratriptan with screen-printed electrodes.

PubMed

Hernández, Carla Navarro; Martín-Yerga, Daniel; González-García, María Begoña; Hernández-Santos, David; Fanjul-Bolado, Pablo

2018-02-01

Naratriptan, active pharmaceutical ingredient with antimigraine activity was electrochemically detected in untreated screen-printed carbon electrodes (SPCEs). Cyclic voltammetry and differential pulse voltammetry were used to carry out quantitative analysis of this molecule (in a Britton-Robinson buffer solution at pH 3.0) through its irreversible oxidation (diffusion controlled) at a potential of +0.75V (vs. Ag pseudoreference electrode). Naratriptan oxidation product is an indole based dimer with a yellowish colour (maximum absorption at 320nm) so UV-VIS spectroelectrochemistry technique was used for the very first time as an in situ characterization and quantification technique for this molecule. A reflection configuration approach allowed its measurement over the untreated carbon based electrode. Finally, time resolved Raman Spectroelectrochemistry is used as a powerful technique to carry out qualitative and quantitative analysis of Naratriptan. Electrochemically treated silver screen-printed electrodes are shown as easy to use and cost-effective SERS substrates for the analysis of Naratriptan. Copyright © 2017 Elsevier B.V. All rights reserved.

Amperometric Sensor for Detection of Chloride Ions.

PubMed

Trnkova, Libuse; Adam, Vojtech; Hubalek, Jaromir; Babula, Petr; Kizek, Rene

2008-09-15

Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO₃, a solution of AgNO₃ and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO₃, solution of AgNO₃ and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV) we estimated the limit of detection (3 S/N) as 500 nM.

Record Efficiency on Large Area P-Type Czochralski Silicon Substrates

NASA Astrophysics Data System (ADS)

Hallam, Brett; Wenham, Stuart; Lee, Haeseok; Lee, Eunjoo; Lee, Hyunwoo; Kim, Jisun; Shin, Jeongeun; Cho, Kyeongyeon; Kim, Jisoo

2012-10-01

In this work we report a world record independently confirmed efficiency of 19.4% for a large area p-type Czochralski grown solar cell fabricated with a full area aluminium back surface field. This is achieved using the laser doped selective emitter solar cell technology on an industrial screen print production line with the addition of laser doping and light induced plating equipment. The use of a modified diffusion process is explored in which the emitter is diffused to a sheet resistance of 90 Ω/square and subsequent etch back of the emitter to 120 Ω/square. This results in a lower surface concentration of phosphorus compared to that of emitters diffused directly to 120 Ω/square. This modified diffusion process subsequently reduces the conductivity of the surface in relation to that of the heavily diffused laser doped contacts and avoids parasitic plating, resulting an average absolute increase in efficiency of 0.4% compared to cells fabricated without an emitter etch back process.

Molybdenum disulphide and graphene quantum dots as electrode modifiers for laccase biosensor.

PubMed

Vasilescu, Ioana; Eremia, Sandra A V; Kusko, Mihaela; Radoi, Antonio; Vasile, Eugeniu; Radu, Gabriel-Lucian

2016-01-15

A nanocomposite formed from molybdenum disulphide (MoS2) and graphene quantum dots (GQDs) was proposed as a novel and suitable support for enzyme immobilisation displaying interesting electrochemical properties. The conductivity of the carbon based screen-printed electrodes was highly improved after modification with MoS2 nanoflakes and GQDs, the nanocomposite also providing compatible matrix for laccase immobilisation. The influence of different modification steps on the final electroanalytical performances of the modified electrode were evaluated by UV-vis absorption and fluorescence spectroscopy, scanning electron microscopy, transmission electron microscopy, X ray diffraction, electrochemical impedance spectroscopy and cyclic voltammetry. The developed laccase biosensor has responded efficiently to caffeic acid over a concentration range of 0.38-100µM, had a detection limit of 0.32µM and a sensitivity of 17.92nAµM(-1). The proposed analytical tool was successfully applied for the determination of total polyphenolic content from red wine samples. Copyright © 2015 Elsevier B.V. All rights reserved.

A novel paper-based device coupled with a silver nanoparticle-modified boron-doped diamond electrode for cholesterol detection.

PubMed

Nantaphol, Siriwan; Chailapakul, Orawon; Siangproh, Weena

2015-09-03

A novel paper-based analytical device (PAD) coupled with a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode was first developed as a cholesterol sensor. The AgNP/BDD electrode was used as working electrode after modification by AgNPs using an electrodeposition method. Wax printing was used to define the hydrophilic and hydrophobic areas on filter paper, and then counter and reference electrodes were fabricated on the hydrophilic area by screen-printing in house. For the amperometric detection, cholesterol and cholesterol oxidase (ChOx) were directly drop-cast onto the hydrophilic area, and H2O2 produced from the enzymatic reaction was monitored. The fabricated device demonstrated a good linearity (0.39 mg dL(-1) to 270.69 mg dL(-1)), low detection limit (0.25 mg dL(-1)), and high sensitivity (49.61 μA mM(-1) cm(-2)). The precision value for ten replicates was 3.76% RSD for 1 mM H2O2. In addition, this biosensor exhibited very high selectivity for cholesterol detection and excellent recoveries for bovine serum analysis (in the range of 99.6-100.8%). The results showed that this new sensing platform will be an alternative tool for cholesterol detection in routine diagnosis and offers the advantages of low sample/reagent consumption, low cost, portability, and short analysis time. Copyright © 2015 Elsevier B.V. All rights reserved.

Fire-retardant decorative inks for aircraft interiors

NASA Technical Reports Server (NTRS)

Kourtides, D. A.; Nir, Z.; Mikroyannidis, J. A.

1985-01-01

Commercial and experimental fire retardants were screened as potential fire retardants for acrylic printing inks used on aircraft interior sandwich panels. The fire retardants are selected according to their physical properties and their thermostabilities. A criterion for selecting a more stable fire retardant is established. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are used to determine thermostabilities. Results show that the fire retardant formulations are more thermally stable than the acrylic ink control. It is determined that an ink formulation containing a brominated phenol and carboxy-terminated butadiene acrylonitrile which has been modified with a brominated polymeric additive (BPA), yields the highest limiting oxygen index (LOI) of all the compounds tested. All of the fire-retardant formulations have a higher oxygen index than the baseline acrylic ink.

A Randomized Trial to Compare Alternative Educational Interventions to Increase Colorectal Cancer Screening in a Hard-to-Reach Urban Minority Population with Health Insurance.

PubMed

Basch, Charles E; Zybert, Patricia; Wolf, Randi L; Basch, Corey H; Ullman, Ralph; Shmukler, Celia; King, Fionnuala; Neugut, Alfred I; Shea, Steven

2015-10-01

This randomized controlled trial assessed different educational approaches for increasing colorectal cancer screening uptake in a sample of primarily non-US born urban minority individuals, over aged 50, with health insurance, and out of compliance with screening guidelines. In one group, participants were mailed printed educational material (n = 180); in a second, participants' primary care physicians received academic detailing to improve screening referral and follow-up practices (n = 185); in a third, physicians received academic detailing and participants received tailored telephone education (n = 199). Overall, 21.5% of participants (n = 121) received appropriate screening within one year of randomization. There were no statistically significant pairwise differences between groups in screening rate. Among those 60 years of age or older, however, the detailing plus telephone education group had a higher screening rate than the print group (27.3 vs. 7.7%, p = .02). Different kinds of interventions will be required to increase colorectal cancer screening among the increasingly small population segment that remains unscreened. ClinicalTrials.gov Identifier: NCT02392143.

Effect of sintering temperatures and screen printing types on TiO{sub 2} layers in DSSC applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Supriyanto, Agus; Furqoni, Lutfi; Nurosyid, Fahru, E-mail: nurosyid@yahoo.com

2016-03-29

Dye-Sensitized Solar Cell (DSSC) is a candidate solar cell, which has a big potential in the future due to its eco-friendly material. This research is conducted to study the effect of sintering temperature and the type of screen-printing toward the characteristics of TiO{sub 2} layer as a working electrode in DSSC. TiO{sub 2} layers were fabricated using a screen-printing method with a mesh size of T-49, T-55, and T-61. TiO{sub 2} layers were sintered at temperatures of 600°C and 650°C for 60 min. DSSC structure was composed of TiO{sub 2} as semiconductors, ruthenium complex as dyes, and carbon as counter electrodes.more » The morphology of TiO{sub 2} layer was observed by using Nikon E2 Digital Camera Microscopy. The efficiencies of DSSC were calculated from the I-V curves. The highest efficiency is 0.015% at TiO{sub 2} layer fabricated with screen type T-61 and at a sintering temperature of 650°C.« less

Reaction of photochemical resists used in screen printing under the influence of digitally modulated ultra violet light

NASA Astrophysics Data System (ADS)

Gmuender, T.

2017-02-01

Different chemical photo-reactive emulsions are used in screen printing for stencil production. Depending on the bandwidth, optical power and depth of field from the optical system, the reaction / exposure speed has a diverse value. In this paper, the emulsions get categorized and validated in a first step. After that a mathematical model gets developed and adapted due to heuristic experience to estimate the exposure speed under the influence of digitally modulated ultra violet (UV) light. The main intention is to use the technical specifications (intended wavelength, exposure time, distance to the stencil, electrical power, stencil configuration) in the emulsion data sheet primary written down with an uncertainty factor for the end user operating with large projector arc lamps and photo films. These five parameters are the inputs for a mathematical formula which gives as an output the exposure speed for the Computer to Screen (CTS) machine calculated for each emulsion / stencil setup. The importance of this work relies in the possibility to rate with just a few boundaries the performance and capacity of an exposure system used in screen printing instead of processing a long test series for each emulsion / stencil configuration.

Characterization of polymer silver pastes for screen printed flexible RFID antennas

NASA Astrophysics Data System (ADS)

Janeczek, Kamil; Jakubowska, Małgorzata; Futera, Konrad; MłoŻniak, Anna; Kozioł, GraŻyna; Araźna, Aneta

Radio Frequency Identification (RFID) systems have become more and more popular in the last few years because of their wide application fields, such as supply chain management and logistics. To continue their development further investigations of new conductive materials for fabrication of RFID transponders' antennas are necessary to be carried out. These materials should provide high flexibility and good radiation performance of printed antennas. In this paper, two polymer silver pastes based on silver flakes were characterized with regard to manufacturing of flexible RFID antennas with screen printing technique. Foil and paper were used as a substrate materials. Surface profile of the printed antennas was measured using an optical profilometer and their resistance was measured with a four-point-probe method. Antenna flexibility was evaluated in cyclic bending tests and its performance with reflection coefficient measurements with the use of differential probe connected to a vector network analyzer. In addition, a maximum read distance of a fabricated RFID transponder was measured.

Biosensing with Paper-Based Miniaturized Printed Electrodes-A Modern Trend.

PubMed

Silveira, Célia M; Monteiro, Tiago; Almeida, Maria Gabriela

2016-09-28

From the bench-mark work on microfluidics from the Whitesides's group in 2007, paper technology has experienced significant growth, particularly regarding applications in biomedical research and clinical diagnostics. Besides the structural properties supporting microfluidics, other advantageous features of paper materials, including their versatility, disposability and low cost, show off the great potential for the development of advanced and eco-friendly analytical tools. Consequently, paper was quickly employed in the field of electrochemical sensors, being an ideal material for producing custom, tailored and miniaturized devices. Stencil-, inkjet-, or screen-printing are the preferential techniques for electrode manufacturing. Not surprisingly, we witnessed a rapid increase in the number of publications on paper based screen-printed sensors at the turn of the past decade. Among the sensing strategies, various biosensors, coupling electrochemical detectors with biomolecules, have been proposed. This work provides a critical review and a discussion on the future progress of paper technology in the context of miniaturized printed electrochemical biosensors.

Biosensing with Paper-Based Miniaturized Printed Electrodes–A Modern Trend

PubMed Central

Silveira, Célia M.; Monteiro, Tiago; Almeida, Maria Gabriela

2016-01-01

From the bench-mark work on microfluidics from the Whitesides’s group in 2007, paper technology has experienced significant growth, particularly regarding applications in biomedical research and clinical diagnostics. Besides the structural properties supporting microfluidics, other advantageous features of paper materials, including their versatility, disposability and low cost, show off the great potential for the development of advanced and eco-friendly analytical tools. Consequently, paper was quickly employed in the field of electrochemical sensors, being an ideal material for producing custom, tailored and miniaturized devices. Stencil-, inkjet-, or screen-printing are the preferential techniques for electrode manufacturing. Not surprisingly, we witnessed a rapid increase in the number of publications on paper based screen-printed sensors at the turn of the past decade. Among the sensing strategies, various biosensors, coupling electrochemical detectors with biomolecules, have been proposed. This work provides a critical review and a discussion on the future progress of paper technology in the context of miniaturized printed electrochemical biosensors. PMID:27690119

A printed, dry electrode Frank configuration vest for ambulatory vectorcardiographic monitoring

NASA Astrophysics Data System (ADS)

Paul, Gordon; Torah, Russel; Beeby, Steve; Tudor, John

2017-02-01

This paper describes the design and fabrication of a screen printed network of bio-potential measurement electrodes on a garment, in this case a vest. The electrodes are placed according to the Frank configuration, which allows monitoring of the electrical behavior of the heart in three spatial orientations. The vest is designed to provide stable contact pressure on the electrodes. The electrodes are fabricated from stencil printed carbon loaded rubber and are connected by screen printed silver polymer conductive tracks to an array of vias, which form an electrical connection to the other side of the textile. The vest is tested and compared to Frank configuration recordings that were obtained using standard self-adhesive ECG electrodes. The vest was successfully used to obtain Frank configuration recordings with minimal baseline drift. The vest is fabricated using only technologies found in standard textile production lines and can be used with a reduced setup effort compared to clinical 12-lead examinations.

A graphene-based electrochemical competitive immunosensor for the sensitive detection of okadaic acid in shellfish

NASA Astrophysics Data System (ADS)

Eissa, Shimaa; Zourob, Mohammed

2012-11-01

A novel graphene-based voltammetric immunosensor for sensitive detection of okadaic acid (OA) was developed. A simple and efficient electrografting method was utilized to functionalize graphene-modified screen-printed carbon electrodes (GSPE) by the electrochemical reduction of in situ generated 4-carboxyphenyl diazonium salt in acidic aqueous solution. Next, the okadaic acid antibody was covalently immobilized on the carboxyphenyl modified graphene electrodes via carbodiimide chemistry. Square wave voltammetry (SWV) was used to investigate the stepwise assembly of the immunosensor. A competitive assay between OA and a fixed concentration of okadaic acid-ovalbumin conjugate (OA-OVA) for the immobilized antibodies was employed for the detection of okadaic acid. The decrease of the [Fe(CN)6]3-/4- reduction peak current in the square wave voltammetry for various concentrations of okadaic acid was used for establishing the calibration curve. A linear relationship between the SWV peak current difference and OA concentration was obtained up to ~5000 ng L-1. The developed immunosensor allowed a detection limit of 19 ng L-1 of OA in PBS buffer. The matrix effect studied with spiked shellfish tissue extracts showed a good percentage of recovery and the method was also validated with certified reference mussel samples.A novel graphene-based voltammetric immunosensor for sensitive detection of okadaic acid (OA) was developed. A simple and efficient electrografting method was utilized to functionalize graphene-modified screen-printed carbon electrodes (GSPE) by the electrochemical reduction of in situ generated 4-carboxyphenyl diazonium salt in acidic aqueous solution. Next, the okadaic acid antibody was covalently immobilized on the carboxyphenyl modified graphene electrodes via carbodiimide chemistry. Square wave voltammetry (SWV) was used to investigate the stepwise assembly of the immunosensor. A competitive assay between OA and a fixed concentration of okadaic acid-ovalbumin conjugate (OA-OVA) for the immobilized antibodies was employed for the detection of okadaic acid. The decrease of the [Fe(CN)6]3-/4- reduction peak current in the square wave voltammetry for various concentrations of okadaic acid was used for establishing the calibration curve. A linear relationship between the SWV peak current difference and OA concentration was obtained up to ~5000 ng L-1. The developed immunosensor allowed a detection limit of 19 ng L-1 of OA in PBS buffer. The matrix effect studied with spiked shellfish tissue extracts showed a good percentage of recovery and the method was also validated with certified reference mussel samples. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32146g

Four-Dimensional Screening Anti-Counterfeiting Pattern by Inkjet Printed Photonic Crystals.

PubMed

Hou, Jue; Zhang, Huacheng; Su, Bin; Li, Mingzhu; Yang, Qiang; Jiang, Lei; Song, Yanlin

2016-10-06

A four-dimensional screening anti-counterfeiting QR code composed of differently shaped photonic crystal (PC) dots has been fabricated that could display four images depending on different lighting conditions. By controlling the rheology of poly(dimethylsiloxane) (PDMS), three kinds of PC dots could be sequentially integrated into one pattern using the layer-by-layer printing strategy. The information can be encoded and stored in shapes and read out by the difference in optical properties. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Screening for Peripheral Artery Disease

MedlinePlus

... Disclosures Acknowledgments Footnotes Figures & Tables Info & Metrics eLetters Article Tools Print Citation Tools Screening for Peripheral Artery ... Remember my user name & password. Submit Share this Article Email Thank you for your interest in spreading ...

Ink-jet printing of silver metallization for photovoltaics

NASA Technical Reports Server (NTRS)

Vest, R. W.

1986-01-01

The status of the ink-jet printing program at Purdue University is described. The drop-on-demand printing system was modified to use metallo-organic decomposition (MOD) inks. Also, an IBM AT computer was integrated into the ink-jet printer system to provide operational functions and contact pattern configuration. The integration of the ink-jet printing system, problems encountered, and solutions derived were described in detail. The status of ink-jet printing using a MOD ink was discussed. The ink contained silver neodecanate and bismuth 2-ethylhexanoate dissolved in toluene; the MOD ink decomposition products being 99 wt% AG, and 1 wt% Bi.

Choosing a CD-ROM Encyclopedia: How to Critically Evaluate the Product.

ERIC Educational Resources Information Center

Dickinson, Gail

1990-01-01

Offers criteria for the critical evaluation of CD-ROM encyclopedias. Differences between CD-ROM and print encyclopedias are discussed; search strategies are explained; evaluation criteria are suggested, including help messages, screen format, indexing method, and graphics and print options; future considerations are suggested, including…

Iconographic dental typography. A dental character font for computer graphics.

PubMed

McCormack, J

1991-06-08

The recent massive increase in available memory for microcomputers now allows multiple font faces to be stored in computer RAM memory for instant access to the screen and for printed output. Fonts can be constructed in which the characters are not just letters or numbers, but are miniature graphic icons--in this instance pictures of teeth. When printed on an appropriate laser printer, this produces printed graphics of publishing quality.

Smart textile framework: Photochromic and fluorescent cellulosic fabric printed by strontium aluminate pigment.

PubMed

Khattab, Tawfik A; Rehan, Mohamed; Hamouda, Tamer

2018-09-01

Smart clothing can be defined as textiles that respond to a certain stimulus accompanied by a change in their properties. A specific class herein is the photochromic and fluorescent textiles that change color with light. A photochromic and fluorescent cotton fabric based on pigment printing is obtained. Such fabric is prepared by aqueous-based pigment-binder printing formulation containing inorganic pigment phosphor characterized by good photo- and thermal stability. It exhibits optimal excitation wavelength (365 nm) results in color and fluorescence change of the fabric surface. To prepare the transparent pigment-binder composite film, the phosphor pigment must be well-dispersed via physical immobilization without their aggregation. The pigment-binder paste is applied successfully onto cotton fabric using screen printing technique followed by thermal fixation. After screen-printing, a homogenous photochromic film is assembled on a cotton substrate surface, which represents substantial greenish-yellow color development as indicated by CIE Lab color space measurements under ultraviolet light, even at a pigment concentration of 0.08 wt% of the printing paste. The photochromic cotton fabric exhibit three excitation peaks at 272, 325 and 365 nm and three emission peaks at 418, 495 and 520 nm. The fluorescent optical microscope, scanning electron microscope, elemental mapping, energy dispersive X-ray spectroscopy, fluorescence emission and UV/Vis absorption spectroscopic data of the printed cotton fabric are described. The printed fabric showed a reversible and rapid photochromic response during ultra-violet excitation without fatigue. The fastness properties including washing, crocking, perspiration, sublimation/heat, and light are described. Copyright © 2018 Elsevier Ltd. All rights reserved.

Highly Sensitive and Selective Hydrogen Gas Sensor Using the Mesoporous SnO2 Modified Layers

PubMed Central

Xue, Niuzi; Zhang, Qinyi; Zhang, Shunping; Zong, Pan; Yang, Feng

2017-01-01

It is important to improve the sensitivities and selectivities of metal oxide semiconductor (MOS) gas sensors when they are used to monitor the state of hydrogen in aerospace industry and electronic field. In this paper, the ordered mesoporous SnO2 (m-SnO2) powders were prepared by sol-gel method, and the morphology and structure were characterized by X-ray diffraction analysis (XRD), transmission electron microscope (TEM) and Brunauer–Emmett–Teller (BET). The gas sensors were fabricated using m-SnO2 as the modified layers on the surface of commercial SnO2 (c-SnO2) by screen printing technology, and tested for gas sensing towards ethanol, benzene and hydrogen with operating temperatures ranging from 200 °C to 400 °C. Higher sensitivity was achieved by using the modified m-SnO2 layers on the c-SnO2 gas sensor, and it was found that the S(c/m2) sensor exhibited the highest response (Ra/Rg = 22.2) to 1000 ppm hydrogen at 400 °C. In this paper, the mechanism of the sensitivity and selectivity improvement of the gas sensors is also discussed. PMID:29036898

Self-assembly of glucose oxidase on reduced graphene oxide-magnetic nanoparticles nanocomposite-based direct electrochemistry for reagentless glucose biosensor.

PubMed

Pakapongpan, Saithip; Poo-Arporn, Rungtiva P

2017-07-01

A novel approach of the immobilization of a highly selective and stable glucose biosensor based on direct electrochemistry was fabricated by a self-assembly of glucose oxidase (GOD) on reduced graphene oxide (RGO) covalently conjugated to magnetic nanoparticles (Fe 3 O 4 NPs) modified on a magnetic screen-printed electrode (MSPE). The RGO-Fe 3 O 4 nanocomposite has remarkable enhancement in large surface areas, is favorable environment for enzyme immobilization, facilitates electron transfer between enzymes and electrode surfaces and possesses superparamagnetism property. The morphology and electrochemical properties of RGO-Fe 3 O 4 /GOD were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, cyclic voltammetry (CV) and amperometry. The modified electrode was a fast, direct electron transfer with an apparent electron transfer rate constant (k s ) of 13.78s -1 . The proposed biosensor showed fast amperometric response (3s) to glucose with a wide linear range from 0.05 to 1mM, a low detection limit of 0.1μM at a signal to noise ratio of 3 (S/N=3) and good sensitivity (5.9μA/mM). The resulting biosensor has high stability, good reproducibility, excellent selectivity and successfully applied detection potential at -0.45V. This mediatorless glucose sensing used the advantages of covalent bonding and self-assembly as a new approach for immobilizing enzymes without any binder. It would be worth noting that it opens a new avenue for fabricating excellent electrochemical biosensors. This is a new approach that reporting the immobilization of glucose oxidase on reduced graphene oxide (RGO) covalently conjugated to magnetic nanoparticles (Fe 3 O 4 NPs) by electrostatic interaction and modified screen printed electrode. We propose the reagentless with fabrication method without binder and adhesive agents for immobilized enzyme. Fe 3 O 4 NPs increasing surface area to enhance the immobilization and prevent the leaching of enzymes at electrode surfaces by magnetic stickers which is improve the stability of the biosensor. Based on this synthesis technique, it is a good new strategy and simple used to fabrication of third-generation glucose biosensor and this nanocomposite could be used as a platform for disposable biosensor and biofuel cell applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Get Your Teen Screened for Depression

MedlinePlus

... Depression Print This Topic En español Get Your Teen Screened for Depression Browse Sections The Basics Overview ... 8 of 9 sections Take Action: Support Your Teen Find resources for your teen. If your child ...

3-D printed composites with ultrasonically arranged complex microstructure

NASA Astrophysics Data System (ADS)

Llewellyn-Jones, Thomas M.; Drinkwater, Bruce W.; Trask, Richard S.

2016-04-01

This paper demonstrates the efficacy of implementing ultrasonic manipulation within a modified form of stereolithographic 3D printing to form complex microstructures in printed components. Currently 3D printed components are limited both in terms of structural performance and specialised functionality. This study aims to demonstrate a novel method for 3D printing composite materials, by arranging microparticles suspended within a photocurable resin. The resin is selectively cured by a 3-axis gantry-mounted 405nm laser. Ultrasonic forces are used to arrange the microfibres into predetermined patterns within the resin, with unidirectional microfibre alignment and a hexagonal lattice structure demonstrated. An example of dynamic microstructure variation within a single print layer is also presented.

Coverage of breast cancer in the Australian print media--does advertising and editorial coverage reflect correct social marketing messages?

PubMed

Jones, Sandra C

2004-01-01

Early detection of breast cancer by mammographic screening has the potential to dramatically reduce mortality rates, but many women do not comply with screening recommendations. The media are an important source of health information for many women--through both direct social marketing advertisements and indirect dissemination of information via editorial content. This study investigated the accuracy of breast cancer detection messages in the top-selling Australian women's magazines and three weekend newspapers in the six-month period from December 2000 to May 2001 that included any reference to breast cancer and found that current coverage of breast cancer in the Australian print media conveys messages that are unlikely to encourage appropriate screening.

Reading Touch Screen Storybooks with Mothers Negatively Affects 7-Year-Old Readers’ Comprehension but Enriches Emotional Engagement

PubMed Central

Ross, Kirsty M.; Pye, Rachel E.; Randell, Jordan

2016-01-01

Touch screen storybooks turn reading into an interactive multimedia experience, with hotspot-activated animations, sound effects, and games. Positive and negative effects of reading multimedia stories have been reported, but the underlying mechanisms which explain how children’s learning is affected remain uncertain. The present study examined the effect of storybook format (touch screen and print) on story comprehension, and considered how level of touch screen interactivity (high and low) and shared reading behaviors (cognitive and emotional scaffolding, emotional engagement) might contribute to comprehension. Seven-year-olds (n = 22) were observed reading one touch screen storybook and one print storybook with their mothers. Story comprehension was inferior for the touch screen storybooks compared to the print formats. Touch screen interactivity level had no significant effect on comprehension but did affect shared reading behaviors. The mother–child dyads spent less time talking about the story in the highly interactive touch screen condition, despite longer shared reading sessions because of touch screen interactions. Positive emotional engagement was greater for children and mothers in the highly interactive touch screen condition, due to additional positive emotions expressed during touch screen interactions. Negative emotional engagement was greater for children when reading and talking about the story in the highly interactive condition, and some mothers demonstrated negative emotional engagement with the touch screen activities. The less interactive touch screen storybook had little effect on shared reading behaviors, but mothers controlling behaviors were more frequent. Storybook format had no effect on the frequency of mothers’ cognitive scaffolding behaviors (comprehension questions, word help). Relationships between comprehension and shared reading behaviors were examined for each storybook, and although length of the shared reading session and controlling behaviors had significant effects on comprehension, the mechanisms driving comprehension were not fully explained by the data. The potential for touch screen storybooks to contribute to cognitive overload in 7-year-old developing readers is discussed, as is the complex relationship between cognitive and emotional scaffolding behaviors, emotional engagement, and comprehension. Sample characteristics and methodological limitations are also discussed to help inform future research. PMID:27899903

Tablet-Based eBooks for Young Children: What Does the Research Say?

PubMed

Reich, Stephanie M; Yau, Joanna C; Warschauer, Mark

2016-09-01

Young children's use of electronic books (eBooks) is increasing as handheld touch screen devices, such as tablets, become increasingly available. Although older children's reading on tablets has been more broadly investigated, less is known about the impacts of digital reading for infant, toddlers, and preschoolers. This review compares the educational affordances of reading on tablets versus print books for young children's learning. A qualitative synthesis of research on tablet-based eReading and young children's learning from screens was conducted. When eBooks are designed well, preschool-aged children learn equally well and sometimes more than from print books. However, enhanced eBooks with sounds, animations, and games can distract children and reduce learning. When book-sharing with an adult, conversations during eBook reading are often about the platform while print book conversations are more often about the book content. For young children (0-2 yr), there is a paucity of research, but broader studies on learning from screens suggest limited educational benefits of tablet use for this age group. The authors recommend that (1) the selection of eBooks (especially enhanced eBooks) be thoughtful as games or animations that are not related to the story content can be distracting for young children, (2) adults share in the reading experience as discussions of the story, text, and characters have been found to enhance comprehension, language development, and print awareness, and (3) tablet eBook use be restricted for infants and toddlers, as they benefit more from face-to-face interaction with caregivers than from interactive screens alone.

Printed strain sensors for early damage detection in engineering structures

NASA Astrophysics Data System (ADS)

Zymelka, Daniel; Yamashita, Takahiro; Takamatsu, Seiichi; Itoh, Toshihiro; Kobayashi, Takeshi

2018-05-01

In this paper, we demonstrate the analysis of strain measurements recorded using a screen-printed sensors array bonded to a metal plate and subjected to high strains. The analysis was intended to evaluate the capabilities of the printed strain sensors to detect abnormal strain distribution before actual defects (cracks) in the analyzed structures appear. The results demonstrate that the developed device can accurately localize the enhanced strains at the very early stage of crack formation. The promising performance and low fabrication cost confirm the potential suitability of the printed strain sensors for applications within the framework of structural health monitoring (SHM).

Review of Batteryless Wireless Sensors Using Additively Manufactured Microwave Resonators.

PubMed

Memon, Muhammad Usman; Lim, Sungjoon

2017-09-09

The significant improvements observed in the field of bulk-production of printed microchip technologies in the past decade have allowed the fabrication of microchip printing on numerous materials including organic and flexible substrates. Printed sensors and electronics are of significant interest owing to the fast and low-cost fabrication techniques used in their fabrication. The increasing amount of research and deployment of specially printed electronic sensors in a number of applications demonstrates the immense attention paid by researchers to this topic in the pursuit of achieving wider-scale electronics on different dielectric materials. Although there are many traditional methods for fabricating radio frequency (RF) components, they are time-consuming, expensive, complicated, and require more power for operation than additive fabrication methods. This paper serves as a summary/review of improvements made to the additive printing technologies. The article focuses on three recently developed printing methods for the fabrication of wireless sensors operating at microwave frequencies. The fabrication methods discussed include inkjet printing, three-dimensional (3D) printing, and screen printing.

Review of Batteryless Wireless Sensors Using Additively Manufactured Microwave Resonators

PubMed Central

2017-01-01

The significant improvements observed in the field of bulk-production of printed microchip technologies in the past decade have allowed the fabrication of microchip printing on numerous materials including organic and flexible substrates. Printed sensors and electronics are of significant interest owing to the fast and low-cost fabrication techniques used in their fabrication. The increasing amount of research and deployment of specially printed electronic sensors in a number of applications demonstrates the immense attention paid by researchers to this topic in the pursuit of achieving wider-scale electronics on different dielectric materials. Although there are many traditional methods for fabricating radio frequency (RF) components, they are time-consuming, expensive, complicated, and require more power for operation than additive fabrication methods. This paper serves as a summary/review of improvements made to the additive printing technologies. The article focuses on three recently developed printing methods for the fabrication of wireless sensors operating at microwave frequencies. The fabrication methods discussed include inkjet printing, three-dimensional (3D) printing, and screen printing. PMID:28891947

A quartz-based micro catalytic methane sensor by high resolution screen printing

NASA Astrophysics Data System (ADS)

Lu, Wenshuai; Jing, Gaoshan; Bian, Xiaomeng; Yu, Hongyan; Cui, Tianhong

2016-02-01

A micro catalytic methane sensor was proposed and fabricated on a bulk fused quartz substrate using a high resolution screen printing technique for the first time, with reduced power consumption and optimized sensitivity. The sensor was designed by the finite element method and quartz was chosen as the substrate material and alumina support with optimized dimensions. Fabrication of the sensor consisted of two MEMS processes, lift-off and high resolution screen printing, with the advantages of high yield and uniformity. When the sensor’s regional working temperature changes from 250 °C to 470 °C, its sensitivity increases, as well as the power consumption. The highest sensitivity can reach 1.52 mV/% CH4. A temperature of 300 °C was chosen as the optimized working temperature, and the sensor’s sensitivity, power consumption, nonlinearity and response time are 0.77 mV/% CH4, 415 mW, 2.6%, and 35 s, respectively. This simple, but highly uniform fabrication process and the reliable performance of this sensor may lead to wide applications for methane detection.

Mod silver metallization: Screen printing and ink-jet printing

NASA Technical Reports Server (NTRS)

Vest, R. W.; Vest, G. M.

1985-01-01

Basic material efforts have proven to be very successful. Adherent and conductive films were achieved. A silver neodecanoate/bismuth 2-ethylhexanoate mixture has given the best results in both single and double layer applications. Another effort is continuing to examine the feasibility of applying metallo-organic deposition films by use of an ink jet printer. Direct line writing would result in a saving of process time and materials. So far, some well defined lines have been printed.

The influence of surface modification on sound absorption coefficient of albizzia wood absorber

NASA Astrophysics Data System (ADS)

Diharjo, Kuncoro; Prabowo, Anditya E.; Jamasri, Suharty, Neng Sri

2017-01-01

The purpose of this research is to investigate the influence of surface modification to sound absorption on absorber based albizia wood and kenaf fiber. The absorber was produced using the albizia wood as main materials, and the kenaf fiber was used as acoustic fill. The albizia wood used for producing the absorber was cut in the transverse direction so that its surface had good porosity. The size of specimens had 100 mm in diameter and 40 mm in thickness. The configuration of resonator cavities was 30 mm in diameter and 20 mm in depth, and each resonator was completed with a neck hole of the resonator. The types of surface modification were the addition of screen printing ink, fabric (with and without neck hole), and vinyl-wallpaper (with and without neck hole). According to ISO 10534-2, the absorber specimens were tested using two microphones impedance tube with random noise source to get the curve of noise absorption coefficient (NAC) for each specimen. The result shows that both unmodified absorber and absorber modified with screen printing ink have the similar characteristic of NAC and they are feasible to be used as an absorber in conversation rooms. The addition of fabric and vinyl-wallpaper as cover on the absorber surface give the positive effect of the air gap, and it increases the NAC in low frequency (100-400 Hz). However, the covers decrease the NAC in high frequency (400-1,400 Hz). The holes on the fabric and wallpaper covers give the improvement of NAC.

Versatile Molecular Silver Ink Platform for Printed Flexible Electronics.

PubMed

Kell, Arnold J; Paquet, Chantal; Mozenson, Olga; Djavani-Tabrizi, Iden; Deore, Bhavana; Liu, Xiangyang; Lopinski, Gregory P; James, Robert; Hettak, Khelifa; Shaker, Jafar; Momciu, Adrian; Ferrigno, Julie; Ferrand, Olivier; Hu, Jian Xiong; Lafrenière, Sylvie; Malenfant, Patrick R L

2017-05-24

A silver molecular ink platform formulated for screen, inkjet, and aerosol jet printing is presented. A simple formulation comprising silver neodecanoate, ethyl cellulose, and solvent provides improved performance versus that of established inks, yet with improved economics. Thin, screen-printed traces with exceptional electrical (<10 mΩ/□/mil or 12 μΩ·cm) and mechanical properties are achieved following thermal or photonic sintering, the latter having never been demonstrated for silver-salt-based inks. Low surface roughness, submicron thicknesses, and line widths as narrow as 41 μm outperform commercial ink benchmarks based on flakes or nanoparticles. These traces are mechanically robust to flexing and creasing (less than 10% change in resistance) and bind strongly to epoxy-based adhesives. Thin traces are remarkably conformal, enabling fully printed metal-insulator-metal band-pass filters. The versatility of the molecular ink platform enables an aerosol jet-compatible ink that yields conductive features on glass with 2× bulk resistivity and strong adhesion to various plastic substrates. An inkjet formulation is also used to print top source/drain contacts and demonstrate printed high-mobility thin film transistors (TFTs) based on semiconducting single-walled carbon nanotubes. TFTs with mobility values of ∼25 cm 2 V -1 s -1 and current on/off ratios >10 4 were obtained, performance similar to that of evaporated metal contacts in analogous devices.

Coplanar back contacts for thin silicon solar cells

NASA Technical Reports Server (NTRS)

Thornhill, J. W.; Sipperly, W. E.

1980-01-01

A process for fabricating 2 to 3 mil wraparound solar cells was formulated. Sample thin wraparound cells were fabricated using this process. The process used a reinforced perimeter construction to reduce the breakage that occurs during handling of the wafers. A retracting piston post was designed and fabricated to help minimize the breakage that occurs during the screen printing process. Two alternative methods of applying the aluminum back surface field were investigated. In addition to the standard screen printed back surface field, both spin-on and evaporated aluminum techniques were researched. Neither spin-on nor evaporated aluminum made any noticeable improvement over the screen printing technique. A fine screen mesh was chosen for the application of the aluminum paste back surface field. The optimum time and temperature for firing the aluminum turned out to be thirty seconds at 850 C. The development work on the dielectric included looking at three dielectrics for the wraparound application. Transene 1000, Thick Film Systems 1126RCB and an in house formulation 61-2-2A were all tested. Cells with pre-dielectric thickness of 3.0-0-3.5 mils using Transene 1000 as the wraparound dielectric and the procedure outlined above showed an average efficiency of 10.7 percent. Thinner cells were fabricated, but had an unacceptable yield and efficiency.

A Bridge between Pictures and Print.

ERIC Educational Resources Information Center

Jeffree, Dorothy

1981-01-01

The experiment investigated the feasibility of bridging the gap between the recognition of pictures and the recognition of words in four mentally handicapped adolescents by adapting a modified version of symbol accentuation (in which a printed word looks like the object it represents). (SB)

High performance screen-printed electrodes prepared by a green solvent approach for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Gören, A.; Mendes, J.; Rodrigues, H. M.; Sousa, R. E.; Oliveira, J.; Hilliou, L.; Costa, C. M.; Silva, M. M.; Lanceros-Méndez, S.

2016-12-01

New inks based on lithium iron phosphate and graphite for cathode and anode, respectively, were developed for printable lithium-ion batteries using the "green solvent" N,N‧-dimethylpropyleneurea (DMPU) and poly(vinylidene fluoride), PVDF, as a binder. The results were compared with the ones from inks developed with the conventionally used solvent N-methyl-2-pyrrolidone, NMP. The rheological properties of the PVDF/DMPU binder solution shows a more pronounced shear thinning behavior than the PVDF/NMP solution. Cathode inks prepared with 2.25 mL and 2.50 mL of DMPU for 1 g of electrode mass show an apparent viscosity of 3 Pa s and 2 Pa s for a shear rate of 100 s-1, respectively, being therefore processable by screen-printing or doctor blade techniques. The electrodes prepared with DMPU and processed by screen-printing show a capacity of 52 mAh g-1 at 2C for the cathode and 349 mAh g-1 at C/5 for the anode, after 45 charge-discharge cycles. The electrochemical performance of both electrodes was evaluated in a full-cell and after 9 cycles, the discharge capacity value is 81 mAh g-1, showing a discharge capacity retention of 64%. The new inks presented in this work are thus suitable for the development of printed batteries and represent a step forward towards more environmental friendly processes.

Basics of Compounding: 3D Printing--Pharmacy Applications: Geometric Shape Effects on 3D Printing.

PubMed

Allen, Loyd V

2017-01-01

As patient therapy becomes more specialized and individualized, one applicable method of drug delivery is through 3D printing. With 3D printing, pharmacists can provide either immediate or modified drug release of either an individual drug or multiple drugs in a singledosage unit. The release rates can be varied, not only by excipients in the formulation, but also to some extent by the shapes of the finished-drug preparation. Some studies demonstrating these concepts are included in this article, along with their method of compounding using 3D printing. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

A screen-printed circular-type paper-based glucose/O2 biofuel cell

NASA Astrophysics Data System (ADS)

Shitanda, Isao; Nohara, Saki; Hoshi, Yoshinao; Itagaki, Masayuki; Tsujimura, Seiya

2017-08-01

The printable paper-based enzymatic biofuel cell (PBFC) to directly power small devices is an important objective for realizing cost-effective and disposable energy harvesting devices. In the present study, a screen-printed circular-type PBFC, composed of a series of 5 individual cells, was constructed. The PBFC exhibited the open circuit potential of 2.65 V and maximum power of 350 μW at 1.55 V, which were sufficient to illuminate an LED without requiring a booster circuit. The output voltage of this PBFC can also be easily adjusted as required.

Visualization of nanoconstructions with DNA-Aptamers for targeted molecules binding on the surface of screen-printed electrodes

NASA Astrophysics Data System (ADS)

Lapin, Ivan N.; Shabalina, Anastasiia V.; Svetlichyi, Valery A.; Kolovskaya, Olga S.

2018-04-01

Nanoconstructions of gold nanoparticles (NPs) obtained via pulsed laser ablation in liquid with DNA-aptamer specific to protein tumor marker were visualized on the surface of screen-printed electrode using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). AuNPs/aptamer nanoconstuctions distribution on the solid surface was studied. More uniform coverage of the carbon electrode surface with the nanoconstuctions was showed in comparison with DNA-aptamer alone on the golden electrode surface. Targeted binding of the tumor marker molecules with the AuNPs/DNA-aptamer nanoconstuctions was approved.

Ultraflexible and robust graphene supercapacitors printed on textiles for wearable electronics applications

NASA Astrophysics Data System (ADS)

Abdelkader, Amr M.; Karim, Nazmul; Vallés, Cristina; Afroj, Shaila; Novoselov, Kostya S.; Yeates, Stephen G.

2017-09-01

Printed graphene supercapacitors have the potential to empower tomorrow’s wearable electronics. We report a solid-state flexible supercapacitor device printed on textiles using graphene oxide ink and a screen-printing technique. After printing, graphene oxide was reduced in situ via a rapid electrochemical method avoiding the use of any reducing reagents that may damage the textile substrates. The printed electrodes exhibited excellent mechanical stability due to the strong interaction between the ink and textile substrate. The unique hierarchical porous structure of the electrodes facilitated ionic diffusion and maximised the surface area available for the electrolyte/active material interface. The obtained device showed outstanding cyclic stability over 10 000 cycles and maintained excellent mechanical flexibility, which is necessary for wearable applications. The simple printing technique is readily scalable and avoids the problems associated with fabricating supercapacitor devices made of conductive yarn, as previously reported in the literature.

Improving the Yule-Nielsen modified Neugebauer model by dot surface coverages depending on the ink superposition conditions

NASA Astrophysics Data System (ADS)

Hersch, Roger David; Crété, Frédérique

2004-12-01

Dot gain is different when dots are printed alone, printed in superposition with one ink or printed in superposition with two inks. In addition, the dot gain may also differ depending on which solid ink the considered halftone layer is superposed. In a previous research project, we developed a model for computing the effective surface coverage of a dot according to its superposition conditions. In the present contribution, we improve the Yule-Nielsen modified Neugebauer model by integrating into it our effective dot surface coverage computation model. Calibration of the reproduction curves mapping nominal to effective surface coverages in every superposition condition is carried out by fitting effective dot surfaces which minimize the sum of square differences between the measured reflection density spectra and reflection density spectra predicted according to the Yule-Nielsen modified Neugebauer model. In order to predict the reflection spectrum of a patch, its known nominal surface coverage values are converted into effective coverage values by weighting the contributions from different reproduction curves according to the weights of the contributing superposition conditions. We analyze the colorimetric prediction improvement brought by our extended dot surface coverage model for clustered-dot offset prints, thermal transfer prints and ink-jet prints. The color differences induced by the differences between measured reflection spectra and reflection spectra predicted according to the new dot surface estimation model are quantified on 729 different cyan, magenta, yellow patches covering the full color gamut. As a reference, these differences are also computed for the classical Yule-Nielsen modified spectral Neugebauer model incorporating a single halftone reproduction curve for each ink. Taking into account dot surface coverages according to different superposition conditions considerably improves the predictions of the Yule-Nielsen modified Neugebauer model. In the case of offset prints, the mean difference between predictions and measurements expressed in CIE-LAB CIE-94 ΔE94 values is reduced at 100 lpi from 1.54 to 0.90 (accuracy improvement factor: 1.7) and at 150 lpi it is reduced from 1.87 to 1.00 (accuracy improvement factor: 1.8). Similar improvements have been observed for a thermal transfer printer at 600 dpi, at lineatures of 50 and 75 lpi. In the case of an ink-jet printer at 600 dpi, the mean ΔE94 value is reduced at 75 lpi from 3.03 to 0.90 (accuracy improvement factor: 3.4) and at 100 lpi from 3.08 to 0.91 (accuracy improvement factor: 3.4).

Improving the Yule-Nielsen modified Neugebauer model by dot surface coverages depending on the ink superposition conditions

NASA Astrophysics Data System (ADS)

Hersch, Roger David; Crete, Frederique

2005-01-01

Dot gain is different when dots are printed alone, printed in superposition with one ink or printed in superposition with two inks. In addition, the dot gain may also differ depending on which solid ink the considered halftone layer is superposed. In a previous research project, we developed a model for computing the effective surface coverage of a dot according to its superposition conditions. In the present contribution, we improve the Yule-Nielsen modified Neugebauer model by integrating into it our effective dot surface coverage computation model. Calibration of the reproduction curves mapping nominal to effective surface coverages in every superposition condition is carried out by fitting effective dot surfaces which minimize the sum of square differences between the measured reflection density spectra and reflection density spectra predicted according to the Yule-Nielsen modified Neugebauer model. In order to predict the reflection spectrum of a patch, its known nominal surface coverage values are converted into effective coverage values by weighting the contributions from different reproduction curves according to the weights of the contributing superposition conditions. We analyze the colorimetric prediction improvement brought by our extended dot surface coverage model for clustered-dot offset prints, thermal transfer prints and ink-jet prints. The color differences induced by the differences between measured reflection spectra and reflection spectra predicted according to the new dot surface estimation model are quantified on 729 different cyan, magenta, yellow patches covering the full color gamut. As a reference, these differences are also computed for the classical Yule-Nielsen modified spectral Neugebauer model incorporating a single halftone reproduction curve for each ink. Taking into account dot surface coverages according to different superposition conditions considerably improves the predictions of the Yule-Nielsen modified Neugebauer model. In the case of offset prints, the mean difference between predictions and measurements expressed in CIE-LAB CIE-94 ΔE94 values is reduced at 100 lpi from 1.54 to 0.90 (accuracy improvement factor: 1.7) and at 150 lpi it is reduced from 1.87 to 1.00 (accuracy improvement factor: 1.8). Similar improvements have been observed for a thermal transfer printer at 600 dpi, at lineatures of 50 and 75 lpi. In the case of an ink-jet printer at 600 dpi, the mean ΔE94 value is reduced at 75 lpi from 3.03 to 0.90 (accuracy improvement factor: 3.4) and at 100 lpi from 3.08 to 0.91 (accuracy improvement factor: 3.4).

The efficacy of tailored print materials in promoting colorectal cancer screening: results from a randomized trial involving callers to the National Cancer Institute's Cancer Information Service.

PubMed

Marcus, Alfred C; Mason, Mondi; Wolfe, Pam; Rimer, Barbara K; Lipkus, Isaac; Strecher, Victor; Warneke, Richard; Morra, Marion E; Allen, Amy Reasinger; Davis, Sharon W; Gaier, Amy; Graves, Carlan; Julesberg, Karen; Nguyen, Lynne; Perocchia, Rosemarie; Speyer, Jo Beth; Wagner, Doug; Thomsen, Chris; Bright, Mary Anne

2005-01-01

In this large randomized trial among callers to the Cancer Information Service (CIS), tailored print materials were tested for efficacy in promoting colorectal cancer (CRC) screening (fecal occult blood test [FOBT], flexible sigmoidoscopy, or colonoscopy). All participants completed baseline interviews at the end of their usual service calls to the CIS, as well as short-term (6-month) and longer-term (14-month) telephone follow-up interviews. The study sample (n = 4,014) was restricted to English-speaking CIS callers 50 + years of age, who would be eligible for CRC screening at 14 months follow-up and did not call the CIS about CRC or CRC screening. Four experimental conditions were compared: a single untailored (SU) mailout of print material (the control condition); a single tailored (ST) mailout of print material; four (multiple) tailored (MT) mailouts of print materials spanning 12 months, all of which were tailored to information obtained at baseline; and four (multiple) retailored (MRT) mailouts also spanning 12 months, with retailoring of the print materials (mailouts 2, 3, and 4) based on updated information obtained from the 6-month follow-up interviews. Consistent with the main hypothesis of this trial, a significant linear trend across the SU, ST, MT, and MRT groups was found at 14 months (42%, 44%, 51%, and 48%, respectively, p = 0.05). Only for MT was there a significant difference compared with SU (p = 0.03) for the sample as a whole, while no differences were found for MT vs. MRT at 14 months. Significant moderator effects in the predicted direction were found among females, younger participants, and among those with a history of CRC screening, all of which involved the SU vs. MT MRT comparisons. Only among younger participants (ages 50-59) was there a difference between SU vs. ST at 14 months. Given these results, we conclude from this trial the following: (1) the MRT intervention failed to show added benefit beyond the MT intervention, (2) the significant intervention effects involving the MT and MRT conditions can be explained by tailoring and/or the longitudinal nature of both interventions, and (3) the most compelling evidence in support of tailoring was found for the ST condition among younger participants, where a significant need for interventions exists at the national level. Directions for future research are discussed in light of the results summarized above.

Three-Dimensional Printing with Biomass-Derived PEF for Carbon-Neutral Manufacturing.

PubMed

Kucherov, Fedor A; Gordeev, Evgeny G; Kashin, Alexey S; Ananikov, Valentine P

2017-12-11

Biomass-derived poly(ethylene-2,5-furandicarboxylate) (PEF) has been used for fused deposition modeling (FDM) 3D printing. A complete cycle from cellulose to the printed object has been performed. The printed PEF objects created in the present study show higher chemical resistance than objects printed with commonly available materials (acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), glycol-modified poly(ethylene terephthalate) (PETG)). The studied PEF polymer has shown key advantages for 3D printing: optimal adhesion, thermoplasticity, lack of delamination and low heat shrinkage. The high thermal stability of PEF and relatively low temperature that is necessary for extrusion are optimal for recycling printed objects and minimizing waste. Several successive cycles of 3D printing and recycling were successfully shown. The suggested approach for extending additive manufacturing to carbon-neutral materials opens a new direction in the field of sustainable development. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct Desktop Printed-Circuits-on-Paper Flexible Electronics

PubMed Central

Zheng, Yi; He, Zhizhu; Gao, Yunxia; Liu, Jing

2013-01-01

There currently lacks of a way to directly write out electronics, just like printing pictures on paper by an office printer. Here we show a desktop printing of flexible circuits on paper via developing liquid metal ink and related working mechanisms. Through modifying adhesion of the ink, overcoming its high surface tension by dispensing machine and designing a brush like porous pinhead for printing alloy and identifying matched substrate materials among different papers, the slightly oxidized alloy ink was demonstrated to be flexibly printed on coated paper, which could compose various functional electronics and the concept of Printed-Circuits-on-Paper was thus presented. Further, RTV silicone rubber was adopted as isolating inks and packaging material to guarantee the functional stability of the circuit, which suggests an approach for printing 3D hybrid electro-mechanical device. The present work paved the way for a low cost and easygoing method in directly printing paper electronics.

Ultrasensitive electrochemical immunosensors for multiplexed determination using mesoporous platinum nanoparticles as nonenzymatic labels.

PubMed

Cui, Zhentao; Wu, Dan; Zhang, Yong; Ma, Hongmin; Li, He; Du, Bin; Wei, Qin; Ju, Huangxian

2014-01-07

An ultrasensitive multiplexed immunoassay method was developed at a disposable immunosensor array using mesoporous platinum nanoparticles (M-Pt NPs) as nonenzymatic labels. M-Pt NPs were prepared by ultrasonic method and employed to label the secondary antibody (Ab2) for signal amplification. The immunosensor array was constructed by covalently immobilizing capture antibody (Ab1) on graphene modified screen printed carbon electrodes (SPECs). After the sandwich-type immunoreactions, the M-Pt-Ab2 was bound to immunosensor surface to catalyze the electro-reduction of H2O2 reaction, which produced detectable signals for readout of analytes. Using breast cancer related panel of tumor markers (CA125, CA153 and CEA) as model analytes, this method showed wide linear ranges of over 4 orders of magnitude with the detection limits of 0.002 U mL(-1), 0.001 U mL(-1) and 7.0 pg mL(-1) for CA125, CA153 and CEA, respectively. The disposable immunosensor array possessed excellent clinical value in cancer screening as well as convenient point of care diagnostics. Copyright © 2013 Elsevier B.V. All rights reserved.

ScreenCube: A 3D Printed System for Rapid and Cost-Effective Chemical Screening in Adult Zebrafish.

PubMed

Monstad-Rios, Adrian T; Watson, Claire J; Kwon, Ronald Y

2018-02-01

Phenotype-based small molecule screens in zebrafish embryos and larvae have been successful in accelerating pathway and therapeutic discovery for diverse biological processes. Yet, the application of chemical screens to adult physiologies has been relatively limited due to additional demands on cost, space, and labor associated with screens in adult animals. In this study, we present a 3D printed system and methods for intermittent drug dosing that enable rapid and cost-effective chemical administration in adult zebrafish. Using prefilled screening plates, the system enables dosing of 96 fish in ∼3 min, with a 10-fold reduction in drug quantity compared to that used in previous chemical screens in adult zebrafish. We characterize water quality kinetics during immersion in the system and use these kinetics to rationally design intermittent dosing regimens that result in 100% fish survival. As a demonstration of system fidelity, we show the potential to identify two known chemical inhibitors of adult tail fin regeneration, cyclopamine and dorsomorphin. By developing methods for rapid and cost-effective chemical administration in adult zebrafish, this study expands the potential for small molecule discovery in postembryonic models of development, disease, and regeneration.

High work function materials for source/drain contacts in printed polymer thin film transistors

NASA Astrophysics Data System (ADS)

Sholin, V.; Carter, S. A.; Street, R. A.; Arias, A. C.

2008-02-01

Studies of materials for source-drain electrodes in ink-jet printed polymer-based thin film transistors (TFTs) are reported. Two systems are studied: a blend of Ag nanoparticles with poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) and an ethylene glycol-doped PEDOT:PSS solution (modified-PEDOT). The semiconductor used is the polythiophene derivative poly [5,5'-bis(3-dodecyl-2-thienyl)-2,2,2'-bithiophene]. PEDOT:Ag blends and modified-PEDOT yield TFTs with mobilities around 10-2 and 10-3cm2/Vs, respectively, subthreshold slopes around 1.6V/decade and on-to-off current ratios of 106-107. Both systems show considerable improvement over printed TFTs with Ag nanoparticle source-drain electrodes. Results on film resistivity and morphology are discussed along with device characteristic analysis.

Screening for digital printing: a multiparameter task

NASA Astrophysics Data System (ADS)

Daels, Katrien; Delabastita, Paul A.

1997-02-01

Changing demands in advertising and printing business has made the digital press systems valid competitors to offset technology for specific markets. Whereas offset is still superior in quality and high volume printing, the time consuming and costly prepress activities, as well as the need for huge investments in the press, make the all-in-one formula very attractive. How to link a fast/cheap machine with decent output-quality, making use of electrophotography? We use electrophotography as a pretext for making a stability analysis of several halftoning systems. As shown in a previous article (Ref. 3) we use the Fourier characteristics to figure out its dependence. In a first introduction we point out why electrophotography brings us to this matter. The further outline of the article scans through a list of opposite screening systems where we focus on the color stability in function of registration.

A multi-component nanocomposite screen-printed ink with non-linear touch sensitive electrical conductivity

NASA Astrophysics Data System (ADS)

Webb, Alexander J.; Szablewski, Marek; Bloor, David; Atkinson, Del; Graham, Adam; Laughlin, Paul; Lussey, David

2013-04-01

Printable electronics is an innovative area of technology with great commercial potential. Here, a screen-printed functional ink, comprising a combination of semiconducting acicular particles, electrically insulating nanoparticles and a base polymer ink, is described that exhibits pronounced pressure sensitive electrical properties for applications in sensing and touch sensitive surfaces. The combination of these components in the as-printed ink yield a complex structure and a large and reproducible touch pressure sensitive resistance range. In contrast to the case for some composite systems, the resistance changes occur down to applied pressures of 13 Pa. Current-voltage measurements at fixed pressures show monotonic non-linear behaviour, which becomes more Ohmic at higher pressures and in all cases shows some hysteresis. The physical basis for conduction, particularly in the low pressure regime, can be described in terms of field assisted quantum mechanical tunnelling.

Construction and performance characterization of screen printed and carbon paste ion selective electrodes for potentiometric determination of naphazoline hydrochloride in pharmaceutical preparations.

PubMed

Frag, Eman Y Z; Mohamed, Gehad G; El-Dien, F A Nour; Mohamed, Marwa E

2011-01-21

This paper describes the development of screen-printed (SPE) and carbon paste (CPE) sensors for the rapid and sensitive quantification of naphazoline hydrochloride (NPZ) in pharmaceutical formulations. This work compares the electroactivity of conventional carbon paste and screen-printed carbon paste electrodes towards potentiometric titration of NPZ. The repeatability and accuracy of measurements performed in the analysis of these pharmaceutical matrices using new screen printed sensors were evaluated. The influence of the electrode composition, conditioning time of the electrode and pH of the test solution, on the electrode performance were investigated. The drug electrode showed Nernstain responses in the concentration range from 1 × 10(-6) to 1 × 10(-2) mol L(-1) with slopes of 57.5 ± 1.3 and 55.9 ± 1.6 mV per decade for SPE and CPE, respectively, and was found to be very precise and usable within the pH range 3-8. These sensors exhibited a fast response time (about 3 s for both SPE and CPE, respectively), a low detection limit (3.5 × 10(-6) and 1.5 × 10(-6) M for SPE and CPE, respectively), a long lifetime (3 and 2 months for SPE and CPE, respectively) and good stability. The selectivity of the electrode toward a large number of inorganic cations, sugars and amino acids was tested. It was applied to potentiometric determination of NPZ in pure state and pharmaceutical preparation under batch conditions. The percentage recovery values for the assay of NPZ in tablets (relative standard deviations ≤0.3% for n = 4) were compared well with those obtained by the official method.

REPLACEMENT OF HAZARDOUS MATERIAL IN WIDE WEB FLEXOGRAPHIC PRINTING PROCESS

EPA Science Inventory

This study examined on a technical and economic basis, the effect of substituting water-based inks in a flexographic printing process. To reduce volatile organic compound (VOC) emissions by switching from the use of solvent-based inks to water based inks, several equipment modifi...

Performance of the heavy fraction of pyrolysis oil derived from waste printed circuit boards in modifying asphalt.

PubMed

Yang, Fan; Sun, Shuiyu; Zhong, Sheng; Li, Shenyong; Wang, Yi; Wu, Jiaqi

2013-09-15

The focus of this research was the development of efficient and affordable asphalt modifiers. Pyrolysis oil was produced as a byproduct from the pyrolysis of waste printed circuit boards (WPCBs). The high boiling point fraction was separated from the pyrolysis oil through distillation and is referred to as the heavy fraction of pyrolysis oil (HFPO). The HFPO was tested as an asphalt modifier. Three asphalt modifiers were tested: HFPO; styrene-butadiene rubber (SBR); and HFPO + SBR (1:1). The physical properties and road performance of the three modified asphalts were measured and evaluated. The results have shown that when the amount of modifier was less than 10%, the HFPO modified asphalt had the highest softening point of the three. The dynamic stability (DS) and water resistance of the asphalt mixture with the HFPO modified asphalt was 10,161 cycles/mm and 87.2%, respectively. The DS was much larger than for the HFPO + SBR and SBR modified asphalt mixtures. These results indicate that using HFPO as an asphalt modifier has significant benefits not only for road engineering but also for resource recycling. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reading and Studying on the Screen: An Overview of Literature towards Good Learning Design Practice

ERIC Educational Resources Information Center

Nichols, Mark

2016-01-01

As distance education moves increasingly towards online provision, and because of the benefits provided by online approaches, students will be expected to engage with more resources available on screen. Contemporary forms of reading from the screen include reading from tablet devices, LCD monitors, and smartphones. However, print remains the…

Amperometric Sensor for Detection of Chloride Ions†

PubMed Central

Trnkova, Libuse; Adam, Vojtech; Hubalek, Jaromir; Babula, Petr; Kizek, Rene

2008-01-01

Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV) we estimated the limit of detection (3 S/N) as 500 nM. PMID:27873832

Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds.

PubMed

Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md Rakibul

2016-06-29

A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075-10 µM and 10-55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days.

Synthesis, characterization and electrochemical properties of 5-aza[5]helicene-CH2O-CO-MWCNTs nanocomposite

NASA Astrophysics Data System (ADS)

Fontana, F.; Melone, F.; Iannazzo, D.; Leonardi, S. G.; Neri, G.

2017-03-01

In this study, we report the preparation of a novel nanocomposite, 5-aza[5]helicene-CH2O-CO-MWCNTs, obtained by grafting the 5-aza[5]helicene moiety on the surface of multi-walled carbon nanotubes (MWCNTs). Thermogravimetry (TGA), Fourier transform-infrared spectroscopy (FTIR), ultraviolet (UV), and photoluminescence (PL) measurements provided evidence that the organic moiety is covalently grafted to the MWCNTs. The 5-aza[5]helicene-CH2O-CO-MWCNTs nanocomposite was utilized to fabricate modified commercial screen-printed carbon electrodes. Its electrochemical behavior was studied in neutral buffer solution in the presence of ferricyanide and hydroquinone (HQ). Finally, the electrochemical sensing of epinephrine in the presence of ascorbic acid by using the linear sweep voltammetry (LSV) technique was investigated. Results have demonstrated the enhanced electrocatalytic activity and excellent ability of the 5-aza[5]helicene-CH2O-CO-MWCNTs-modified electrode in the separation between the anodic peaks of epinephrine (EP) and ascorbic acid (AA), even in the presence of a high amount of AA, with a detection limit (S/N = 3) of 5 μmol l-1.

Radiologists' preferences for digital mammographic display. The International Digital Mammography Development Group.

PubMed

Pisano, E D; Cole, E B; Major, S; Zong, S; Hemminger, B M; Muller, K E; Johnston, R E; Walsh, R; Conant, E; Fajardo, L L; Feig, S A; Nishikawa, R M; Yaffe, M J; Williams, M B; Aylward, S R

2000-09-01

To determine the preferences of radiologists among eight different image processing algorithms applied to digital mammograms obtained for screening and diagnostic imaging tasks. Twenty-eight images representing histologically proved masses or calcifications were obtained by using three clinically available digital mammographic units. Images were processed and printed on film by using manual intensity windowing, histogram-based intensity windowing, mixture model intensity windowing, peripheral equalization, multiscale image contrast amplification (MUSICA), contrast-limited adaptive histogram equalization, Trex processing, and unsharp masking. Twelve radiologists compared the processed digital images with screen-film mammograms obtained in the same patient for breast cancer screening and breast lesion diagnosis. For the screening task, screen-film mammograms were preferred to all digital presentations, but the acceptability of images processed with Trex and MUSICA algorithms were not significantly different. All printed digital images were preferred to screen-film radiographs in the diagnosis of masses; mammograms processed with unsharp masking were significantly preferred. For the diagnosis of calcifications, no processed digital mammogram was preferred to screen-film mammograms. When digital mammograms were preferred to screen-film mammograms, radiologists selected different digital processing algorithms for each of three mammographic reading tasks and for different lesion types. Soft-copy display will eventually allow radiologists to select among these options more easily.

Hydrothermal modification and recycling of nonmetallic particles from waste print circuit boards.

PubMed

Gao, Xuehua; Li, Qisheng; Qiu, Jun

2018-04-01

Nonmetallic particles recycled from waste print circuit boards (NPRPs) were modified by a hydrothermal treatment method and the catalysts, solvents, temperature and time were investigated, which affected the modification effect of NPRPs. The mild hydrothermal treatment method does not need high temperature, and would not cause secondary pollution. Further, the modified NPRPs were used as the raw materials for the epoxy resin and glass fibers/epoxy resin composites, which were prepared by pouring and hot-pressing method. The mechanical properties and morphology of the composites were discussed. The results showed that relative intensity of the hydroxyl bonds on the surface of NPRPs increased 58.9% after modification. The mechanical tests revealed that both flexural and impact properties of the composites can be significantly improved by adding the modified NPRPs. Particularly, the maximum increment of flexural strength, flexural modulus and impact strength of the epoxy matrix composites with 30% modified NPRPs is 40.1%, 80.0% and 79.0%, respectively. Hydrothermal treatment can modify surface of NPRPs successfully and modified NPRPs can not only improve the properties of the composites, but also reduce the production cost of the composites and environmental pollution. Thus, we develop a new way to recycle nonmetallic materials of waste print circuit boards and the highest level of waste material recycling with the raw materials-products-raw materials closed cycle can be realized through the hydrothermal modification and reuse of NPRPs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Research on Learners' Preferences for Reading from a Printed Text or from a Computer Screen

ERIC Educational Resources Information Center

Spencer, Carrie

2006-01-01

In this study, 254 Royal Roads University School of Business learners (graduates and undergraduates) were surveyed on their online course-related reading habits and choices. Based on their responses and anecdotal comments and the data from follow-up interviews with six of the participants, learners preferred print copies of text materials for…

Comparison between mixed and spatially separated remote phosphor fabricated via a screen-printing process

NASA Astrophysics Data System (ADS)

Kim, Byung-Ho; Hwang, Jonghee; Lee, Young Jin; Kim, Jin-Ho; Jeon, Dae-Woo; Lee, Mi Jai

2016-08-01

We developed a fabrication method for remote phosphor by a screen-printing process, using green phosphor, red phosphor, and thermally stable glass frit. The glass frit was introduced for long-term stability. The optical properties of the remote phosphor were observed via an integrating sphere; the photoluminescence spectrum dramatically changed on incorporating a minor amount of the red phosphor. These unique optical properties were elucidated using four factors: phosphor ratio, scattering induced by packing density, light intensity per unit volume, and reabsorption. The thermal stability of the remote phosphor was investigated at 500°C, demonstrating its outstanding thermal properties.

Communication—Improving Intermediate-Temperature Performance of a Screen-Printed LSCF Cathode with Infiltrated LSCF Nanoparticles

DOE PAGES

Si, Fengzhan; Zhang, Guoguang; Huang, Kevin

2016-04-09

Here, the present study investigates the mass loading effect of an infiltrated La 0.6Sr 0.4Co 0.2Fe 0.8O 3-δ (LSCF) nanoparticles (NPs) catalyst on the area-specific polarization resistance (Rp) of a screen-printed porous LSCF cathode for solid oxide fuel cells. The results show that R p of the LSCF-NPs decorated LSCF cathode can be substantially reduced by as much as 89.3% after a single-step impregnation of 1.5 M nitrate solution containing La:Sr:Co:Fe = 0.6:0.4:0.2:0.8 with a mass loading of 3 wt%.

New-type planar field emission display with superaligned carbon nanotube yarn emitter.

PubMed

Liu, Peng; Wei, Yang; Liu, Kai; Liu, Liang; Jiang, Kaili; Fan, Shoushan

2012-05-09

With the superaligned carbon nanotube yarn as emitter, we have fabricated a 16 × 16 pixel field emission display prototype by adopting screen printing and laser cutting technologies. A planar diode field emission structure has been adopted. A very sharp carbon nanotube yarn tip emitter can be formed by laser cutting. Low voltage phosphor was coated on the anode electrodes also by screen printing. With a specially designed circuit, we have demonstrated the dynamic character display with the field emission display prototype. The emitter material and fabrication technologies in this paper are both easy to scale up to large areas.

Comparative study of different alcohol sensors based on Screen-Printed Carbon Electrodes.

PubMed

Costa Rama, Estefanía; Biscay, Julien; González García, María Begoña; Julio Reviejo, A; Pingarrón Carrazón, José Manuel; Costa García, Agustín

2012-05-30

Different very simple single-use alcohol enzyme sensors were developed using alcohol oxidase (AOX) from three different yeast, Hansenula sp., Pichia pastoris and Candida boidinii, and employing three different commercial mediator-based Screen-Printed Carbon Electrodes as transducers. The mediators tested, Prussian Blue, Ferrocyanide and Co-phthalocyanine were included into the ink of the working electrode. The procedure to obtain these sensors consists of the immobilization of the enzyme on the electrode surface by adsorption. For the immobilization, an AOX solution is deposited on the working electrode and left until dried (1h) at room temperature. The best results were obtained with the biosensor using Screen-Printed Co-phthalocyanine/Carbon Electrode and AOX from Hansenula sp. The reduced cobalt-phthalocyanine form is amperometrically detected at +0.4V (vs. Ag pseudo reference electrode). This sensor shows good sensitivity (1211 nA mM(-1)), high precision (2.1% RSD value for the slope value of the calibration plot) and wide linear response (0.05-1.00 mM) for ethanol determination. The sensor provides also accurate results for ethanol quantification in alcoholic drinks. Copyright © 2012 Elsevier B.V. All rights reserved.

Electrochemical Affinity Biosensors Based on Disposable Screen-Printed Electrodes for Detection of Food Allergens

PubMed Central

Vasilescu, Alina; Nunes, Gilvanda; Hayat, Akhtar; Latif, Usman; Marty, Jean-Louis

2016-01-01

Food allergens are proteins from nuts and tree nuts, fish, shellfish, wheat, soy, eggs or milk which trigger severe adverse reactions in the human body, involving IgE-type antibodies. Sensitive detection of allergens in a large variety of food matrices has become increasingly important considering the emergence of functional foods and new food manufacturing technologies. For example, proteins such as casein from milk or lysozyme and ovalbumin from eggs are sometimes used as fining agents in the wine industry. Nonetheless, allergen detection in processed foods is a challenging endeavor, as allergen proteins are degraded during food processing steps involving heating or fermentation. Detection of food allergens was primarily achieved via Enzyme-Linked Immuno Assay (ELISA) or by chromatographic methods. With the advent of biosensors, electrochemical affinity-based biosensors such as those incorporating antibodies and aptamers as biorecognition elements were also reported in the literature. In this review paper, we highlight the success achieved in the design of electrochemical affinity biosensors based on disposable screen-printed electrodes towards detection of protein allergens. We will discuss the analytical figures of merit for various disposable screen-printed affinity sensors in relation to methodologies employed for immobilization of bioreceptors on transducer surface. PMID:27827963

Enhanced electrical properties of textured NBBT ceramics derived from the screen printing technique.

PubMed

Wu, Mengjia; Wang, Youliang; Wang, Dong; Li, Yongxiang

2011-10-01

(001)(pc)-oriented (Na(0.5)Bi(0.5))(0.94)Ba(0.06)TiO(3) (NBBT) lead-free piezoelectric ceramics were fabricated by the screen printing technique using Na(0.5)Bi(0.5)TiO(3) (NBT) templates. The plate-like NBT template particles were synthesized from bismuth layer-structured ferroelectric Bi(4)Ti(3)O(12) (BiT) precursors by the topochemical method. The screen printed NBBT ceramics with 20 wt% NBT templates contained a large fraction of grains aligned with their c-axis normal to the sample surface, giving a Lotgering factor of 0.486. The dielectric and ferroelectric properties of textured NBBT ceramics were anisotropic. Compared with the non-textured NBBT ceramics, the dielectric, ferroelectric, and piezoelectric properties of the textured NBBT ceramics were improved, giving a dielectric constant ϵ(T)(33)/ϵ(0) of 910, a remnant polarization P(r) of 29.2 μC/cm(2), a coercive field E(c) of 23.5 kV/cm, a piezoelectric coefficient d(33) of 180 pC/N, and a thickness-mode electromechanical coupling coefficient k(t) of 0.485.

Electrochemical Affinity Biosensors Based on Disposable Screen-Printed Electrodes for Detection of Food Allergens.

PubMed

Vasilescu, Alina; Nunes, Gilvanda; Hayat, Akhtar; Latif, Usman; Marty, Jean-Louis

2016-11-05

Food allergens are proteins from nuts and tree nuts, fish, shellfish, wheat, soy, eggs or milk which trigger severe adverse reactions in the human body, involving IgE-type antibodies. Sensitive detection of allergens in a large variety of food matrices has become increasingly important considering the emergence of functional foods and new food manufacturing technologies. For example, proteins such as casein from milk or lysozyme and ovalbumin from eggs are sometimes used as fining agents in the wine industry. Nonetheless, allergen detection in processed foods is a challenging endeavor, as allergen proteins are degraded during food processing steps involving heating or fermentation. Detection of food allergens was primarily achieved via Enzyme-Linked Immuno Assay (ELISA) or by chromatographic methods. With the advent of biosensors, electrochemical affinity-based biosensors such as those incorporating antibodies and aptamers as biorecognition elements were also reported in the literature. In this review paper, we highlight the success achieved in the design of electrochemical affinity biosensors based on disposable screen-printed electrodes towards detection of protein allergens. We will discuss the analytical figures of merit for various disposable screen-printed affinity sensors in relation to methodologies employed for immobilization of bioreceptors on transducer surface.

Emerging Carbon and Post-Carbon Nanomaterial Inks for Printed Electronics.

PubMed

Secor, Ethan B; Hersam, Mark C

2015-02-19

Carbon and post-carbon nanomaterials present desirable electrical, optical, chemical, and mechanical attributes for printed electronics, offering low-cost, large-area functionality on flexible substrates. In this Perspective, recent developments in carbon nanomaterial inks are highlighted. Monodisperse semiconducting single-walled carbon nanotubes compatible with inkjet and aerosol jet printing are ideal channels for thin-film transistors, while inkjet, gravure, and screen-printable graphene-based inks are better-suited for electrodes and interconnects. Despite the high performance achieved in prototype devices, additional effort is required to address materials integration issues encountered in more complex systems. In this regard, post-carbon nanomaterial inks (e.g., electrically insulating boron nitride and optically active transition-metal dichalcogenides) present promising opportunities. Finally, emerging work to extend these nanomaterial inks to three-dimensional printing provides a path toward nonplanar devices. Overall, the superlative properties of these materials, coupled with versatile assembly by printing techniques, offer a powerful platform for next-generation printed electronics.

Indirect X-ray Detectors Based on Inkjet-Printed Photodetectors with a Screen-Printed Scintillator Layer.

PubMed

Oliveira, Juliana; Correia, Vitor; Sowade, Enrico; Etxebarria, Ikerne; Rodriguez, Raul D; Mitra, Kalyan Y; Baumann, Reinhard R; Lanceros-Mendez, Senentxu

2018-04-18

Organic photodetectors (PDs) based on printing technologies will allow to expand the current field of PD applications toward large-area and flexible applications in areas such as medical imaging, security, and quality control, among others. Inkjet printing is a powerful digital tool for the deposition of smart and functional materials on various substrates, allowing the development of electronic devices such as PDs on various substrates. In this work, inkjet-printed PD arrays, based on the organic thin-film transistor architecture, have been developed and applied for the indirect detection of X-ray radiation using a scintillator ink as an X-ray absorber. The >90% increase of the photocurrent of the PDs under X-ray radiation, from about 53 nA without the scintillator film to about 102 nA with the scintillator located on top of the PD, proves the suitability of the developed printed device for X-ray detection applications.

Research of paste transition to substrate in LTCC-technology

NASA Astrophysics Data System (ADS)

Litunov, S. N.; Yurkov, V. Y.

2018-01-01

The electronics development demands for accuracy of printed technologies, in particular, to screen printing. Under a flat blade operation the print form is deformed and the image is distorted relative to the original. A squeegee in a form of a smooth cylinder reduces distortion, but it allows obtaining satisfactory print quality only when using high density grids. The paper shows findings of using roller squeegee with dosed ink supply. The roller squeegee is provided with an elastic layer. Dosage is carried out due to the cells on the elastic layer surface. There were used meshes 100-31 and 120-34 for the stencil. The experiments were carried out with layers of photopolymers and rubber. The carried out calculations made possible to choose the optimum printing pressure. Under the selected conditions, the printed image had minimal distortion. The findings allow drawing a conclusion about the possibility of roller squeegee using in chips manufacture according to LTCC-technology.

Intimate partner violence and health provider training and screening in the news.

PubMed

Manganello, Jennifer A; Webster, Daniel; Campbell, Jacquelyn C

2006-01-01

Intimate partner violence is a significant women's health issue. Since the news media can play a role in policy development, it is important to understand how newspapers have portrayed training and screening. The purpose of this study was to describe the frequency and nature of print news coverage of health issues related to partner violence, specifically, provider training and screening by health providers. We conducted a content analysis on articles obtained from major city and state capital daily newspapers from 20 states. News articles and editorials mentioning intimate partner violence and provider training and screening were examined for the years 1994 through 2001 (N = 188). Results showed that print news coverage was limited and received low levels of attention, indicating little potential to influence either policy or individual behavior. However, when the issue was covered, little debate or controversy was present, and a broad discussion of the issue was generally provided. News coverage of training and screening could be improved by increasing dissemination of research results, illustrating the policy implications of these issues, and offering resource information to women experiencing violence.

Green synthesis and characterization of novel gold nanocomposites for electrochemical sensing applications.

PubMed

Tanwar, Shivani; Ho, Ja-an Annie; Magi, Emanuele

2013-12-15

Synthesis, characterization and application of Au-PANI-Calix and Au-PANI-Nap nanocomposites, is reported herein. An easy template free green synthesis is proposed and discussed for easy expediency. A variety of analytical techniques were used to characterize the nanocomposites: UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Dynamic light scattering (DLS), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were used to characterize the nanocomposites. Surface morphology was studied by transmission electron microscopy (TEM). The nanocomposites were immobilized on screen-printed electrode and showed electroactivity in neutral pH, making them promising candidates for various analytical applications. A sensitive and selective detection of Cu(2+) was perceived on the Au-PANI-Calix modified electrode with no interference from ions K(+), Ni(2+), Co(2+), Pb(2+), Cr(3+) with a detection limit of 10nM. The copper detection is facilitated for accessible ligation with 4-sulfocalix[4]arene, so as the Cu(II)-Calix complex formed. The electrode modified with Au-PANI-Nap showed sensing application towards H2O2 with a detection limit of 1 μM. The modified electrodes were reproducible and stable for 2 months. © 2013 Elsevier B.V. All rights reserved.

Enhancing the educational value of direct-to-consumer advertising of prescription drugs.

PubMed

Hwang, Monica J; Young, Henry N

The educational value of direct-to-consumer advertising (DTCA) of prescription drugs hinges on its ability to convey important benefit and risk information to consumers. However, the literacy level required to understand some of the information presented in print advertisements may hinder DTCA's ability to educate consumers. The objective of this study was to compare the comprehension and retention of benefit and risk information between consumers who viewed an original print DTCA and those who viewed an advertisement modified according to health literacy principles. An experimental design was used to conduct the study. Participants were randomly assigned to view a modified print advertisement (experimental group) or the original print advertisement (control group) for an antidepressant medication. Study participants were recruited from the University of Wisconsin Kidney Clinic. Ten true-false and 10 multiple-choice questions were developed to assess participants' comprehension and retention of benefit and risk information. A total of 120 participants were randomized to view either the original or the modified version of the advertisement. Regarding the comprehension and retention of only the benefit information, no significant differences were observed between the 2 groups. Significant differences were observed for comprehension and retention of only the risk information. The experimental group had significantly higher scores in comprehension (U = 1224; P < 0.01) and retention (U = 965; P < 0.01) of the risk information compared with the control group. These differences were also significant in multivariate analyses controlling for extraneous variables that were found to have associations with comprehension and retention of information. Study results demonstrated that the health literacy techniques used to modify the advertisement were successful in enhancing both consumers' comprehension and their retention of information presented in a print DTCA. This was especially apparent for the risk information. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

A Disposable Alkaline Phosphatase-Based Biosensor for Vanadium Chronoamperometric Determination

PubMed Central

Alvarado-Gámez, Ana Lorena; Alonso-Lomillo, María Asunción; Domínguez-Renedo, Olga; Arcos-Martínez, María Julia

2014-01-01

A chronoamperometric method for vanadium ion determination, based on the inhibition of the enzyme alkaline phosphatase, is reported. Screen-printed carbon electrodes modified with gold nanoparticles were used as transducers for the immobilization of the enzyme. The enzymatic activity over 4-nitrophenyl phosphate sodium salt is affected by vanadium ions, which results in a decrease in the chronoamperometric current registered. The developed method has a detection limit of 0.39 ± 0.06 μM, a repeatability of 7.7% (n = 4) and a reproducibility of 8% (n = 3). A study of the possible interferences shows that the presence of Mo(VI), Cr(III), Ca(II) and W(VI), may affect vanadium determination at concentration higher than 1.0 mM. The method was successfully applied to the determination of vanadium in spiked tap water. PMID:24569772

DEMONSTRATION OF WATERBASED PLATEN ADHESIVES FOR GARMENT SCREEN PRINTERS

EPA Science Inventory

The paper discusses a demonstration of waterbased platen adhesives as a viable alternative to the organic-based aerosol adhesives that are predominantly used by garment screen printers to affix garments or fabric pieces to print platens. o demonstrate this, the effectiveness of s...

Manufacturing of polylactic acid nanocomposite 3D printer filaments for smart textile applications

NASA Astrophysics Data System (ADS)

Hashemi Sanatgar, R.; Cayla, A.; Campagne, C.; Nierstrasz, V.

2017-10-01

In this paper, manufacturing of polylactic acid nanocomposite 3D printer filaments was considered for smart textile applications. 3D printing process was applied as a novel process for deposition of nanocomposites on PLA fabrics to introduce more flexible, resourceefficient and cost effective textile functionalization processes than conventional printing process like screen and inkjet printing. The aim is to develop an integrated or tailored production process for smart and functional textiles which avoid unnecessary use of water, energy, chemicals and minimize the waste to improve ecological footprint and productivity.

Printed photodetectors

NASA Astrophysics Data System (ADS)

Pace, Giuseppina; Grimoldi, Andrea; Sampietro, Marco; Natali, Dario; Caironi, Mario

2015-10-01

Photodetectors convert light pulses into electrical signals and are fundamental building blocks for any opto-electronic system adopting light as a probe or information carrier. They have widespread technological applications, from telecommunications to sensors in industrial, medical and civil environments. Further opportunities are plastic short-range communications systems, interactive large-area surfaces and light-weight, flexible, digital imagers. These applications would greatly benefit from the cost-effective fabrication processes enabled by printing technology. While organic semiconductors are the most investigated materials for printed photodetectors, and are the main focus of the present review, there are notable examples of other inorganic or hybrid printable semiconductors for opto-electronic systems, such as quantum-dots and nanowires. Here we propose an overview on printed photodetectors, including three-terminal phototransistors. We first give a brief account of the working mechanism of these light sensitive devices, and then we review the recent progress achieved with scalable printing techniques such as screen-printing, inkjet and other non-contact technologies in the development of all-printed or hybrid systems.

3D Printing of Plant Golgi Stacks from Their Electron Tomographic Models.

PubMed

Mai, Keith Ka Ki; Kang, Madison J; Kang, Byung-Ho

2017-01-01

Three-dimensional (3D) printing is an effective tool for preparing tangible 3D models from computer visualizations to assist in scientific research and education. With the recent popularization of 3D printing processes, it is now possible for individual laboratories to convert their scientific data into a physical form suitable for presentation or teaching purposes. Electron tomography is an electron microscopy method by which 3D structures of subcellular organelles or macromolecular complexes are determined at nanometer-level resolutions. Electron tomography analyses have revealed the convoluted membrane architectures of Golgi stacks, chloroplasts, and mitochondria. But the intricacy of their 3D organizations is difficult to grasp from tomographic models illustrated on computer screens. Despite the rapid development of 3D printing technologies, production of organelle models based on experimental data with 3D printing has rarely been documented. In this chapter, we present a simple guide to creating 3D prints of electron tomographic models of plant Golgi stacks using the two most accessible 3D printing technologies.

On demand manufacturing of patient-specific liquid capsules via co-ordinated 3D printing and liquid dispensing.

PubMed

Okwuosa, Tochukwu C; Soares, Cindy; Gollwitzer, Verena; Habashy, Rober; Timmins, Peter; Alhnan, Mohamed A

2018-06-15

A method for the production of liquid capsules with the potential of modifying drug dose and release is presented. For the first time, the co-ordinated use of fused deposition modelling (FDM), 3D printing and liquid dispensing to fabricate individualised dosage form on demand in a fully automated fashion has been demonstrated. Polymethacrylate shells (Eudragit EPO and RL) for immediate and extended release were fabricated using FDM 3D printing and simultaneously filled using a computer-controlled liquid dispenser loaded with model drug solution (theophylline) or suspension (dipyridamole). The impact of printing modes: simultaneous shell printing and filling (single-phase) or sequential 3D printing of shell bottom, filling and shell cap (multi-phase), nozzle size, syringe volume, and shell structure has been reported. The use of shell thickness of 1.6 mm, and concentric architecture allowed successful containment of liquid core whilst maintaining the release properties of the 3D printed liquid capsule. The linear relationship between the theoretical and the actual volumes from the dispenser reflected its potential for accurate dosing (R 2  = 0.9985). Modifying the shell thickness of Eudragit RL capsule allowed a controlled extended drug release without the need for formulation change. Owing to its low cost and versatility, this approach can be adapted to wide spectrum of liquid formulations such as small and large molecule solutions and obviate the need for compatibility with the high temperature of FDM 3D printing process. In a clinical setting, health care staff will be able to instantly manufacture in small volumes liquid capsules with individualised dose contents and release pattern in response to specific patient's needs. Copyright © 2018 Elsevier B.V. All rights reserved.

Office Chromatography: Precise printing of sample solutions on miniaturized thin-layer phases and utilization for scanning Direct Analysis in Real Time mass spectrometry.

PubMed

Häbe, Tim T; Morlock, Gertrud E

2015-09-25

Office Chromatography combines achievements in office technologies with miniaturized planar chromatography. In the life sciences, printing of materials became an accepted technique, whereas in separation science, the use of printers for chromatography is at its infancy. A bubble-jet printer was modified for exact application on miniaturized plates. Technical modifications included the removal of all unnecessary parts and the improvement of the positioning system, purge unit and sample supply system. Evaluation was performed via a slide scanner and image evaluation software. Printing of a food dye mixture solution (n=5) led to a calculated mean deposition volume of 13±1nL/mm(2) per print-cycle. A mean determination coefficient (R(2); n=5) of 0.9990 was obtained for application of increasing volumes, executed via increasing band widths of 50-200μm (corresponding to 2-8nL). Using larger band widths and multiple print jobs, deposition volumes of up to the microliter scale represented an alternative to cost-intensive standard equipment. After print, separation, detection and digital evaluation of five food dyes, mean R(2) (n=5) were obtained between 0.9977 and 0.9995. The accuracy of printing was proven by mean recovery rates of 101-105% with repeatabilities of 3-7% (%RSD, n=5). The transfer to nanostructured ultrathin-layer plates proved the synergetic potential of these fields of research. First, this modified printer was suited for printing of finely graduated scales of three preservatives for determination of the spatial resolution of scanning Direct Analysis in Real Time mass spectrometry. Copyright © 2015 Elsevier B.V. All rights reserved.

Step-by-step guide to building an inexpensive 3D printed motorized positioning stage for automated high-content screening microscopy.

PubMed

Schneidereit, Dominik; Kraus, Larissa; Meier, Jochen C; Friedrich, Oliver; Gilbert, Daniel F

2017-06-15

High-content screening microscopy relies on automation infrastructure that is typically proprietary, non-customizable, costly and requires a high level of skill to use and maintain. The increasing availability of rapid prototyping technology makes it possible to quickly engineer alternatives to conventional automation infrastructure that are low-cost and user-friendly. Here, we describe a 3D printed inexpensive open source and scalable motorized positioning stage for automated high-content screening microscopy and provide detailed step-by-step instructions to re-building the device, including a comprehensive parts list, 3D design files in STEP (Standard for the Exchange of Product model data) and STL (Standard Tessellation Language) format, electronic circuits and wiring diagrams as well as software code. System assembly including 3D printing requires approx. 30h. The fully assembled device is light-weight (1.1kg), small (33×20×8cm) and extremely low-cost (approx. EUR 250). We describe positioning characteristics of the stage, including spatial resolution, accuracy and repeatability, compare imaging data generated with our device to data obtained using a commercially available microplate reader, demonstrate its suitability to high-content microscopy in 96-well high-throughput screening format and validate its applicability to automated functional Cl - - and Ca 2+ -imaging with recombinant HEK293 cells as a model system. A time-lapse video of the stage during operation and as part of a custom assembled screening robot can be found at https://vimeo.com/158813199. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

PyzoFlex: a printed piezoelectric pressure sensing foil for human machine interfaces

NASA Astrophysics Data System (ADS)

Zirkl, M.; Scheipl, G.; Stadlober, B.; Rendl, C.; Greindl, P.; Haller, M.; Hartmann, P.

2013-09-01

Ferroelectric material supports both pyro- and piezoelectric effects that can be used for sensing pressures on large, bended surfaces. We present PyzoFlex, a pressure-sensing input device that is based on a ferroelectric material (PVDF:TrFE). It is constructed by a sandwich structure of four layers that can easily be printed on any substrate. The PyzoFlex foil is sensitive to pressure- and temperature changes, bendable, energy-efficient, and it can easily be produced by a screen-printing routine. Even a hovering input-mode is feasible due to its pyroelectric effect. In this paper, we introduce this novel, fully printed input technology and discuss its benefits and limitations.

"Print-n-Shrink" technology for the rapid production of microfluidic chips and protein microarrays.

PubMed

Sollier, Kevin; Mandon, Céline A; Heyries, Kevin A; Blum, Loïc J; Marquette, Christophe A

2009-12-21

An innovative method for the production of microfluidic chips integrating protein spots is described. The technology, called "Print-n-Shrink", is based on the screen-printing of a microfluidic design (using a dielectric ink) onto Polyshrink polystyrene sheets. The initial print which has a minimum size of 15 microm (height) x 230 microm (width) is thermally treated (30 seconds, 163 degrees C) to shrink and generate features of 85 microm (height) x 100 microm (width). Concomitantly, proteins such as monoclonal antibodies or cellular adhesion proteins are spotted onto the Polyshrink sheets and shrunk together with the microfluidic design, creating a complete biochip integrating both complex microfluidic designs and protein spots for bioanalytical applications.

An ultrasensitive hollow-silica-based biosensor for pathogenic Escherichia coli DNA detection.

PubMed

Ariffin, Eda Yuhana; Lee, Yook Heng; Futra, Dedi; Tan, Ling Ling; Karim, Nurul Huda Abd; Ibrahim, Nik Nuraznida Nik; Ahmad, Asmat

2018-03-01

A novel electrochemical DNA biosensor for ultrasensitive and selective quantitation of Escherichia coli DNA based on aminated hollow silica spheres (HSiSs) has been successfully developed. The HSiSs were synthesized with facile sonication and heating techniques. The HSiSs have an inner and an outer surface for DNA immobilization sites after they have been functionalized with 3-aminopropyltriethoxysilane. From field emission scanning electron microscopy images, the presence of pores was confirmed in the functionalized HSiSs. Furthermore, Brunauer-Emmett-Teller (BET) analysis indicated that the HSiSs have four times more surface area than silica spheres that have no pores. These aminated HSiSs were deposited onto a screen-printed carbon paste electrode containing a layer of gold nanoparticles (AuNPs) to form a AuNP/HSiS hybrid sensor membrane matrix. Aminated DNA probes were grafted onto the AuNP/HSiS-modified screen-printed electrode via imine covalent bonds with use of glutaraldehyde cross-linker. The DNA hybridization reaction was studied by differential pulse voltammetry using an anthraquinone redox intercalator as the electroactive DNA hybridization label. The DNA biosensor demonstrated a linear response over a wide target sequence concentration range of 1.0×10 -12 -1.0×10 -2 μM, with a low detection limit of 8.17×10 -14 μM (R 2 = 0.99). The improved performance of the DNA biosensor appeared to be due to the hollow structure and rough surface morphology of the hollow silica particles, which greatly increased the total binding surface area for high DNA loading capacity. The HSiSs also facilitated molecule diffusion through the silica hollow structure, and substantially improved the overall DNA hybridization assay. Graphical abstract Step-by-step DNA biosensor fabrication based on aminated hollow silica spheres.

Simultaneous Voltammetric Determination of Acetaminophen and Isoniazid (Hepatotoxicity-Related Drugs) Utilizing Bismuth Oxide Nanorod Modified Screen-Printed Electrochemical Sensing Platforms.

PubMed

Mahmoud, Bahaa G; Khairy, Mohamed; Rashwan, Farouk A; Banks, Craig E

2017-02-07

To overcome the recent outbreaks of hepatotoxicity-related drugs, a new analytical tool for the continuously determination of these drugs in human fluids is required. Electrochemical-based analytical methods offer an effective, rapid, and simple tool for on-site determination of various organic and inorganic species. However, the design of a sensitive, selective, stable, and reproducible sensor is still a major challenge. In the present manuscript, a facile, one-pot hydrothermal synthesis of bismuth oxide (Bi 2 O 2.33 ) nanostructures (nanorods) was developed. These BiO nanorods were cast onto mass disposable graphite screen-printed electrodes (BiO-SPEs), allowing the ultrasensitive determination of acetaminophen (APAP) in the presence of its common interference isoniazid (INH), which are both found in drug samples. The simultaneous electroanalytical sensing using BiO-SPEs exhibited strong electrocatalytic activity toward the sensing of APAP and INH with an enhanced analytical signal (voltammetric peak) over that achievable at unmodified (bare) SPEs. The electroanalytical sensing of APAP and INH are possible with accessible linear ranges from 0.5 to 1250 μM and 5 to 1760 μM with limits of detection (3σ) of 30 nM and 1.85 μM, respectively. The stability, reproducibility, and repeatability of BiO-SPE were also investigated. The BiO-SPEs were evaluated toward the sensing of APAP and INH in human serum, urine, saliva, and tablet samples. The results presented in this paper demonstrate that BiO-SPEs sensing platforms provide a potential candidate for the accurate determination of APAP and INH within human fluids and pharmaceutical formulations.

An electrochemical immunosensor for brain natriuretic peptide prepared with screen-printed carbon electrodes nanostructured with gold nanoparticles grafted through aryl diazonium salt chemistry.

PubMed

Serafín, V; Torrente-Rodríguez, R M; González-Cortés, A; García de Frutos, P; Sabaté, M; Campuzano, S; Yáñez-Sedeño, P; Pingarrón, J M

2018-03-01

A sensitive amperometric immunosensor has been prepared by immobilization of capture antibodies onto gold nanoparticles (AuNPs) grafted on a screen-printed carbon electrode (SPCE) through aryl diazonium salt chemistry using 4-aminothiophenol (AuNPs-S-Phe-SPCE). The immunosensor was designed for the accurate determination of clinically relevant levels of B-type natriuretic peptide (BNP) in human serum samples. The nanostructured electrochemical platform resulted in an ordered layer of AuNPs onto SPCEs which combined the advantages of high conductivity and improved stability of immobilized biomolecules. The resulting disposable immunosensor used a sandwich type immunoassay involving a peroxidase-labeled detector antibody. The amperometric transduction was carried out at -0.20V (vs the Ag pseudo-reference electrode) upon the addition of hydroquinone (HQ) as electron transfer mediator and H 2 O 2 as the enzyme substrate. The nanostructured immunosensors show a storage stability of at least 25 days, a linear range between 0.014 and 15ngmL -1 , and a LOD of 4pgmL -1 , which is 100 times lower than the established cut-off value for heart failure (HF) diagnosis. The performance of the immunosensor is advantageously compared with that provided with immunosensors prepared by grafting SPCE with p-phenylendiamine (H 2 N-Phe-SPCE) and attaching AuNPs by immersion into an AuNPs suspension or by electrochemical deposition, as well as with immunosensors constructed using commercial AuNPs-modified SPCEs. The developed immunosensor was applied to the successful analysis of human serum from heart failure (HF) patients upon just a 10-times dilution as sample treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

16 CFR 1500.91 - Determinations regarding lead content for certain materials or products under section 101 of the...

Code of Federal Regulations, 2012 CFR

2012-01-01

... paper which become part of the substrate. (6) CMYK process printing inks (excluding spot colors, other inks that are not used in CMYK process, inks that do not become part of the substrate under 16 CFR part 1303, and inks used in after-treatment applications, including screen prints, transfers, decals, or...

16 CFR 1500.91 - Determinations regarding lead content for certain materials or products under section 101 of the...

Code of Federal Regulations, 2014 CFR

2014-01-01

... paper which become part of the substrate. (6) CMYK process printing inks (excluding spot colors, other inks that are not used in CMYK process, inks that do not become part of the substrate under 16 CFR part 1303, and inks used in after-treatment applications, including screen prints, transfers, decals, or...

16 CFR § 1500.91 - Determinations regarding lead content for certain materials or products under section 101 of the...

Code of Federal Regulations, 2013 CFR

2013-01-01

... paper which become part of the substrate. (6) CMYK process printing inks (excluding spot colors, other inks that are not used in CMYK process, inks that do not become part of the substrate under 16 CFR part 1303, and inks used in after-treatment applications, including screen prints, transfers, decals, or...

16 CFR 1500.91 - Determinations regarding lead content for certain materials or products under section 101 of the...

Code of Federal Regulations, 2011 CFR

2011-01-01

... paper which become part of the substrate. (6) CMYK process printing inks (excluding spot colors, other inks that are not used in CMYK process, inks that do not become part of the substrate under 16 CFR part 1303, and inks used in after-treatment applications, including screen prints, transfers, decals, or...

Helping the Visually Impaired Student with Electronic Video Visual Aids.

ERIC Educational Resources Information Center

Visualtek, Inc., Santa Monica, CA.

THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: Video visual aids are Closed Circuit TV systems (CCTV's) which magnify print and enlarge it electronically upon a screen so partially sighted persons with some residual vision can read and write normal size print. These devices are in use around the world in homes, schools, industries and libraries,…

Just Because You Can Doesn't Mean You Should

ERIC Educational Resources Information Center

Fiehn, Barbara

2016-01-01

When was the last time you saw a student copying from a print reference source? As print sources gather dust, digital materials' use grows. Digital materials are more to the liking of students raised with technology in hand. For young learners, the process of on-screen copy and paste has made replication with pen and paper obsolete. As digital…

Adhesive Stretchable Printed Conductive Thin Film Patterns on PDMS Surface with an Atmospheric Plasma Treatment.

PubMed

Li, Chun-Yi; Liao, Ying-Chih

2016-05-11

In this study, a plasma surface modification with printing process was developed to fabricate printed flexible conductor patterns or devices directly on polydimethylsiloxane (PDMS) surface. An atmospheric plasma treatment was first used to oxidize the PDMS surface and create a hydrophilic silica surface layer, which was confirmed with photoelectron spectra. The plasma operating parameters, such as gas types and plasma powers, were optimized to obtain surface silica layers with the longest lifetime. Conductive paste with epoxy resin was screen-printed on the plasma-treated PDMS surface to fabricate flexible conductive tracks. As a result of the strong binding forces between epoxy resin and the silica surface layer, the printed patterns showed great adhesion on PDMS and were undamaged after several stringent adhesion tests. The printed conductive tracks showed strong mechanical stability and exhibited great electric conductivity under bending, twisting, and stretching conditions. Finally, a printed pressure sensor with good sensitivity and a fast response time was fabricated to demonstrate the capability of this method for the realization of printed electronic devices.

Printable Transparent Conductive Films for Flexible Electronics.

PubMed

Li, Dongdong; Lai, Wen-Yong; Zhang, Yi-Zhou; Huang, Wei

2018-03-01

Printed electronics are an important enabling technology for the development of low-cost, large-area, and flexible optoelectronic devices. Transparent conductive films (TCFs) made from solution-processable transparent conductive materials, such as metal nanoparticles/nanowires, carbon nanotubes, graphene, and conductive polymers, can simultaneously exhibit high mechanical flexibility, low cost, and better photoelectric properties compared to the commonly used sputtered indium-tin-oxide-based TCFs, and are thus receiving great attention. This Review summarizes recent advances of large-area flexible TCFs enabled by several roll-to-roll-compatible printed techniques including inkjet printing, screen printing, offset printing, and gravure printing using the emerging transparent conductive materials. The preparation of TCFs including ink formulation, substrate treatment, patterning, and postprocessing, and their potential applications in solar cells, organic light-emitting diodes, and touch panels are discussed in detail. The rational combination of a variety of printed techniques with emerging transparent conductive materials is believed to extend the opportunities for the development of printed electronics within the realm of flexible electronics and beyond. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Commercial and industrial applications of color ink jet: a technological perspective

NASA Astrophysics Data System (ADS)

Dunand, Alain

1996-03-01

In just 5 years, color ink-jet has become the dominant technology for printing color images and graphics in the office and home markets. In commercial printing, the traditional printing processes are being influenced by new digital techniques. Color ink-jet proofing, and concepts such as computer to film/plate or digital processes are contributing to the evolution of the industry. In industrial color printing, the penetration of digital techniques is just beginning. All widely used conventional contact printing technologies involve mechanical printing forms including plates, screens or engraved cylinders. Such forms, which need to be newly created and set up for each job, increase costs. In our era of fast changing customer demands, growing needs for customization, and increasing use of digital exchange of information, the commercial and industrial printing markets represent an enormous potential for digital printing technologies. The adoption characteristics for the use of color ink-jet in these industries are discussed. Examples of color ink-jet applications in the fields of billboard printing, floor/wall covering decoration, and textile printing are described. The requirements on print quality, productivity, reliability, substrate compatibility, and color lead to the consideration of various types of ink-jet technologies. Key technical enabling factors and directions for future improvements are presented.

Greening up Auto Part Manufacturing: A Collaboration between Academia and Industry

ERIC Educational Resources Information Center

Kneas, Kristi A.; Armstrong, Drew L.; Brank, Alice R.; Johnson, Amanda L.; Kissinger, Chelsea A.; Mabe, Adam R.; Sezer, Ozge; Fontinell, Mike

2009-01-01

Historically, manufacture of automotive electronic components and screen-printing of automotive instrument clusters at DENSO Manufacturing Tennessee, Inc. required washing of equipment such as screens, stencils, and jigs with sizable quantities of volatile organic compounds and hazardous air pollutants. Collaborative efforts between the Maryville…

Highly defined 3D printed chitosan scaffolds featuring improved cell growth.

PubMed

Elviri, Lisa; Foresti, Ruben; Bergonzi, Carlo; Zimetti, Francesca; Marchi, Cinzia; Bianchera, Annalisa; Bernini, Franco; Silvestri, Marco; Bettini, Ruggero

2017-07-12

The augmented demand for medical devices devoted to tissue regeneration and possessing a controlled micro-architecture means there is a need for industrial scale-up in the production of hydrogels. A new 3D printing technique was applied to the automation of a freeze-gelation method for the preparation of chitosan scaffolds with controlled porosity. For this aim, a dedicated 3D printer was built in-house: a preliminary effort has been necessary to explore the printing parameter space to optimize the printing results in terms of geometry, tolerances and mechanical properties of the product. Analysed parameters included viscosity of the starting chitosan solution, which was measured with a Brookfield viscometer, and temperature of deposition, which was determined by filming the process with a cryocooled sensor thermal camera. Optimized parameters were applied to the production of scaffolds from solutions of chitosan alone or with the addition of raffinose as a viscosity modifier. Resulting hydrogels were characterized in terms of morphology and porosity. In vitro cell culture studies comparing 3D printed scaffolds with their homologous produced by solution casting evidenced an improvement in biocompatibility deriving from the production technique as well as from the solid state modification of chitosan stemming from the addition of the viscosity modifier.

Anticounterfeiting features of artistic screening

NASA Astrophysics Data System (ADS)

Ostromoukhov, Victor; Rudaz, Nicolas; Amidror, Isaac; Emmel, Patrick; Hersch, Roger D.

1996-12-01

In a recent publication (Ostromoukhov95), a new image reproduction technique, artistic screening, was presented. It incorporates freely created artistic screen elements for generating halftones. Fixed predefined dot contours associated with given intensity levels determine the screen dot shape's growing behavior. Screen dot contours associated with each intensity level are obtained by interpolation between the fixed predefined dot contours. A user-defined mapping transforms screen elements from screen element definition space to screen element rendition space. This mapping can be tuned to produce various effects such as dilatations, contractions and non-linear deformations of the screen element grid. Although artistic screening has been designed mainly for performing the creation of graphic designs of high artistic quality, it also incorporates several important anti-counterfeiting features. For example, bank notes or other valuable printed matters produced with artistic screening may incorporate both full size and microscopic letters of varying shape into the image halftoning process. Furthermore, artistic screening can be used for generating screen dots at varying frequencies and orientations, which are well known for inducing strong moire effects when scanned by a digital color copier or a desktop scanner. However, it is less known that frequency-modulated screen dots have at each screen element size a different reproduction behavior (dot gain). When trying to reproduce an original by analog means, such as a photocopier, the variations in dot gain induce strong intensity variations at the same original intensity levels. In this paper, we present a method for compensating such variations for the target printer, on which the original security document is to be printed. Potential counterfeiters who would like to reproduce the original with a photocopying device may only be able to adjust the dot gain for the whole image and will therefore be unable to eliminate the undesired intensity variations produced by variable frequency screen elements.

Printing method for organic light emitting device lighting

NASA Astrophysics Data System (ADS)

Ki, Hyun Chul; Kim, Seon Hoon; Kim, Doo-Gun; Kim, Tae-Un; Kim, Snag-Gi; Hong, Kyung-Jin; So, Soon-Yeol

2013-03-01

Organic Light Emitting Device (OLED) has a characteristic to change the electric energy into the light when the electric field is applied to the organic material. OLED is currently employed as a light source for the lighting tools because research has extensively progressed in the improvement of luminance, efficiency, and life time. OLED is widely used in the plate display device because of a simple manufacture process and high emitting efficiency. But most of OLED lighting projects were used the vacuum evaporator (thermal evaporator) with low molecular. Although printing method has lower efficiency and life time of OLED than vacuum evaporator method, projects of printing OLED actively are progressed because was possible to combine with flexible substrate and printing technology. Printing technology is ink-jet, screen printing and slot coating. This printing method allows for low cost and mass production techniques and large substrates. In this research, we have proposed inkjet printing for organic light-emitting devices has the dominant method of thick film deposition because of its low cost and simple processing. In this research, the fabrication of the passive matrix OLED is achieved by inkjet printing, using a polymer phosphorescent ink. We are measured optical and electrical characteristics of OLED.

The role of printing techniques for large-area dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Mariani, Paolo; Vesce, Luigi; Di Carlo, Aldo

2015-10-01

The versatility of printing technologies and their intrinsic ability to outperform other techniques in large-area deposition gives scope to revolutionize the photovoltaic (PV) manufacturing field. Printing methods are commonly used in conventional silicon-based PVs to cover part of the production process. Screen printing techniques, for example, are applied to deposit electrical contacts on the silicon wafer. However, it is with the advent of third generation PVs that printing/coating techniques have been extensively used in almost all of the manufacturing processes. Among all the third generation PVs, dye sensitized solar cell (DSSC) technology has been developed up to commercialization levels. DSSCs and modules can be fabricated by adopting all of the main printing techniques on both rigid and flexible substrates. This allows an easy tuning of cell/module characteristics to the desired application. Transparency, colour, shape, layout and other DSSC’s features can be easily varied by changing the printing parameters and paste/ink formulations used in the printing process. This review focuses on large-area printing/coating technologies for the fabrication of DSSCs devices. The most used and promising techniques are presented underlining the process parameters and applications.

Implementing traceability using particle randomness-based textile printed tags

NASA Astrophysics Data System (ADS)

Agrawal, T. K.; Koehl, L.; Campagne, C.

2017-10-01

This article introduces a random particle-based traceability tag for textiles. The proposed tag not only act as a unique signature for the corresponding textile product but also possess the features such as easy to manufacture and hard to copy. It seeks applications in brand authentication and traceability in textile and clothing (T&C) supply chain. A prototype has been developed by screen printing process, in which micron-scale particles were mixed with the printing paste and printed on cotton fabrics to attain required randomness. To encode the randomness, the image of the developed tag was taken and analyzed using image processing. The randomness of the particles acts as a product key or unique signature which is required to decode the tag. Finally, washing and abrasion resistance tests were conducted to check the durability of the printed tag.

The Effect of All-Capital vs. Regular Mixed Print, as Presented on a Computer Screen, on Reading Rate and Accuracy.

ERIC Educational Resources Information Center

Henney, Maribeth

Two related studies were conducted to determine whether students read all-capital text and mixed text displayed on a computer screen with the same speed and accuracy. Seventy-seven college students read M. A. Tinker's "Basic Reading Rate Test" displayed on a PLATO computer screen. One treatment consisted of paragraphs in all-capital type…

Characterization of screen-printed dye-sensitized nanocrystalline TiO2 solar cells

NASA Astrophysics Data System (ADS)

Gupta, Tapan K.; Cirignano, Leonard J.; Shah, Kanai S.; Moy, Larry P.; Kelly, David J.; Squillante, Michael R.; Entine, Gerald; Smestad, Greg P.

1999-10-01

Titanium dioxide (TiO2) films have been deposited on SnO2 coated glass substrates by screen-printing. Film morphology and structure have been characterized by scanning electron microscopy, x-ray diffraction and BET analysis. Dye-sensitized TiO2 photoelectrochemical cells have been assembled and characterized. Cells sensitized with anthocyanin and a ruthenium complex have been investigated. A 0.77 cm2 ruthenium dye sensitized cell with 6.1% power conversion efficiency under Air Mass (AM1.5) conditions was obtained. Results obtained with a pure anthocyanin dye and dye extracted from blackberries were compared. Finally, a natural gel was found to improve the stability of anthocyanin sensitized cells.

Evaluation of carrier collection probability in bifacial interdigitated-back-contact crystalline silicon solar cells by the internal quantum efficiency mapping method

NASA Astrophysics Data System (ADS)

Tachibana, Tomihisa; Tanahashi, Katsuto; Mochizuki, Toshimitsu; Shirasawa, Katsuhiko; Takato, Hidetaka

2018-04-01

Bifacial interdigitated-back-contact (IBC) silicon solar cells with a high bifaciality of 0.91 were fabricated. Screen printing and firing technology were used to reduce the production cost. For the first time, the relationship between the rear side structure and carrier collection probability was evaluated using internal quantum efficiency (IQE) mapping. The measurement results showed that the screen-printed electrode and back surface field (BSF) area led to low IQE. The low carrier collection probability by BSF area can be explained by electrical shading effects. Thus, it is clear that the IQE mapping system is useful to evaluate the IBC cell.

96X Screen-Printed Gold Electrode Platform to Evaluate Electroactive Polymers as Marine Antifouling Coatings.

PubMed

Brisset, Hugues; Briand, Jean-François; Barry-Martinet, Raphaëlle; Duong, The Hy; Frère, Pierre; Gohier, Frédéric; Leriche, Philippe; Bressy, Christine

2018-04-17

Several alternatives are currently investigated to prevent and control the natural process of colonization of any seawater submerged surfaces by marine organisms. Since few years we develop an approach based on addressable electroactive coatings containing conducting polymers or polymers with lateral redox groups. In this article we describe the use of a screen-printed plate formed by 96 three-electrode electrochemical cells to assess the potential of these electroactive coatings to prevent the adhesion of marine bacteria. This novel platform is intended to control and record the redox properties of the electroactive coating in each well during the bioassay (15 h) and to allow screening its antiadhesion activity with enough replicates to support significant conclusions. Validation of this platform was carried out with poly(ethylenedioxythiophene) (PEDOT) as electroactive coating obtained by electropolymerization of EDOT monomer in artificial seawater electrolyte on the working electrode of each electrochemical cell of the 96-well microplate.

Model-based error diffusion for high fidelity lenticular screening.

PubMed

Lau, Daniel; Smith, Trebor

2006-04-17

Digital halftoning is the process of converting a continuous-tone image into an arrangement of black and white dots for binary display devices such as digital ink-jet and electrophotographic printers. As printers are achieving print resolutions exceeding 1,200 dots per inch, it is becoming increasingly important for halftoning algorithms to consider the variations and interactions in the size and shape of printed dots between neighboring pixels. In the case of lenticular screening where statistically independent images are spatially multiplexed together, ignoring these variations and interactions, such as dot overlap, will result in poor lenticular image quality. To this end, we describe our use of model-based error-diffusion for the lenticular screening problem where statistical independence between component images is achieved by restricting the diffusion of error to only those pixels of the same component image where, in order to avoid instabilities, the proposed approach involves a novel error-clipping procedure.

A Stretchable Radio-Frequency Strain Sensor Using Screen Printing Technology

PubMed Central

Jeong, Heijun; Lim, Sungjoon

2016-01-01

In this paper, we propose a stretchable radio-frequency (RF) strain sensor fabricated with screen printing technology. The RF sensor is designed using a half-wavelength patch that resonates at 3.7 GHz. The resonant frequency is determined by the length of the patch, and it therefore changes when the patch is stretched. Polydimethylsiloxane (PDMS) is used to create the substrate, because of its stretchable and screen-printable surface. In addition, Dupont PE872 (Dupont, NC, American) silver conductive ink is used to create the stretchable conductive patterns. The sensor performance is demonstrated both with full-wave simulations and with measurements carried out on a fabricated sample. When the length of the patch sensor is increased by a 7.8% stretch, the resonant frequency decreases from 3.7 GHz to 3.43 GHz, evidencing a sensitivity of 3.43 × 107 Hz/%. Stretching the patch along its width does not change the resonant frequency. PMID:27827833

Electrochemical Study and Determination of Electroactive Species with Screen-Printed Electrodes

ERIC Educational Resources Information Center

Martín-Yerga, Daniel; Costa Rama, Estefanía; Costa García, Agustín

2016-01-01

A lab appropriate to introduce voltammetric techniques and basic electrochemical parameters is described in this work. It is suitable to study theoretical concepts of electrochemistry in an applied way for analytical undergraduate courses. Two electroactive species, hexaammineruthenium and dopamine, are used as simple redox systems. Screen-printed…

A new photoelectric ink based on nanocellulose/CdS quantum dots for screen-printing.

PubMed

Tang, Aimin; Liu, Yuan; Wang, Qinwen; Chen, Ruisong; Liu, Wangyu; Fang, Zhiqiang; Wang, Lishi

2016-09-05

CdS quantum dots with excellent photoelectrical properties embedded in nanocellulose could be exploited for use in photoelectrical ink. In this work, nanocellulose/CdS quantum dot composites were fabricated by controlling the carboxylate content of the nanocellulose and the molar ratio of Cd(2+)/-COOH. New photoelectric inks were prepared based on the composites, in which the CdS quantum dots acted as the pigment and the nanocellulose as the binder. The results of the photocurrent of the composites showed that the photocurrent could be tailored by the carboxylate content and the molar ratio of Cd(2+)/-COOH. And the photocurrent could be as high as 2μA. The surface tension of the photoelectric ink was 27.80±0.03mN/m and its viscosity was 30.3mPas. The photoelectric ink was stable with excellent fluidity and rheology, it could therefore be applied to screen-printing and three-dimensional (3D) printing. Copyright © 2016 Elsevier Ltd. All rights reserved.

3D Printing of Tissue Engineered Constructs for In Vitro Modeling of Disease Progression and Drug Screening.

PubMed

Vanderburgh, Joseph; Sterling, Julie A; Guelcher, Scott A

2017-01-01

2D cell culture and preclinical animal models have traditionally been implemented for investigating the underlying cellular mechanisms of human disease progression. However, the increasing significance of 3D vs. 2D cell culture has initiated a new era in cell culture research in which 3D in vitro models are emerging as a bridge between traditional 2D cell culture and in vivo animal models. Additive manufacturing (AM, also known as 3D printing), defined as the layer-by-layer fabrication of parts directed by digital information from a 3D computer-aided design file, offers the advantages of simultaneous rapid prototyping and biofunctionalization as well as the precise placement of cells and extracellular matrix with high resolution. In this review, we highlight recent advances in 3D printing of tissue engineered constructs that recapitulate the physical and cellular properties of the tissue microenvironment for investigating mechanisms of disease progression and for screening drugs.

SnO2/Pt Thin Film Laser Ablated Gas Sensor Array

PubMed Central

Shahrokh Abadi, Mohammad Hadi; Hamidon, Mohd Nizar; Shaari, Abdul Halim; Abdullah, Norhafizah; Wagiran, Rahman

2011-01-01

A gas sensor array was developed in a 10 × 10 mm2 space using Screen Printing and Pulse Laser Ablation Deposition (PLAD) techniques. Heater, electrode, and an insulator interlayer were printed using the screen printing method on an alumina substrate, while tin oxide and platinum films, as sensing and catalyst layers, were deposited on the electrode at room temperature using the PLAD method, respectively. To ablate SnO2 and Pt targets, depositions were achieved by using a 1,064 nm Nd-YAG laser, with a power of 0.7 J/s, at different deposition times of 2, 5 and 10 min, in an atmosphere containing 0.04 mbar (4 kPa) of O2. A range of spectroscopic diffraction and real space imaging techniques, SEM, EDX, XRD, and AFM were used in order to characterize the surface morphology, structure, and composition of the films. Measurement on the array shows sensitivity to some solvent and wood smoke can be achieved with short response and recovery times. PMID:22164041

3D Printing of Tissue Engineered Constructs for in vitro Modeling of Disease Progression and Drug Screening

PubMed Central

Vanderburgh, Joseph; Sterling, Julie A.

2016-01-01

2D cell culture and preclinical animal models have traditionally been implemented for investigating the underlying cellular mechanisms of human disease progression. However, the increasing significance of 3D versus 2D cell culture has initiated a new era in cell culture research in which 3D in vitro models are emerging as a bridge between traditional 2D cell culture and in vivo animal models. Additive manufacturing (AM, also known as 3D printing), defined as the layer-by-layer fabrication of parts directed by digital information from a 3D computer-aided design (CAD) file, offers the advantages of simultaneous rapid prototyping and biofunctionalization as well as the precise placement of cells and extracellular matrix with high resolution. In this review, we highlight recent advances in 3D printing of tissue engineered constructs (TECs) that recapitulate the physical and cellular properties of the tissue microenvironment for investigating mechanisms of disease progression and for screening drugs. PMID:27169894

The Effects of Font Type and Spacing of Text for Online Readability and Performance

ERIC Educational Resources Information Center

Hojjati, Nafiseh; Muniandy, Balakrishnan

2014-01-01

Texts are a group of letters which are printed or displayed in a particular style and size. In the course of the fast speed of technological development everywhere and expanding use of computer based instruction such as online courses, students spend more time on a computer screen than printed media. Texts have been the main element to convey…

SET Careers: An interactive science, engineering, and technology career education exhibit. Final report to the United States Department of Energy Science Museum Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, P.R.

1994-04-01

The New York Hall of Science in collaboration with the Educational Film Center and the Consortium for Mathematics and its Applications developed and pilot tested a unique interactive, video-based/hypermedia series on energy related and other science and engineering careers for middle and junior high school students. The United States Department of Energy Science Museum Program supported the development of one energy-related career profile (Susan Fancy--mechanical engineer) and the development and printing of 100 copies of a career-related workbook. Additional funding from the National Science Foundation and the Sloan Foundation resulted in the development of 3 additional career profiles, a relatedmore » Data Base and Career Match Self Assessment for 16 careers, available both on screen and in print in this pilot phase. The SET CAREERS Exhibit is a video-based/hypermedia series which contains profiles of people working in Science, Engineering and Technology fields, interactive opportunities for users including interviews with profiled persons, opportunities to attempt work-related tasks through animated simulations, a Data Base of career-related information available both on-screen and in print, and a Career Match Self Assessment. The screen is in an attract loop mode, inviting visitors to interact with the exhibit. A menu of choices is provided so that users may begin by selecting a profiled person, choosing the Career Match Self Assessment or the Data Base. The Data Base is available in print if the user chooses that mode.« less

A Straightforward Approach for 3D Bacterial Printing

PubMed Central

2017-01-01

Sustainable and personally tailored materials production is an emerging challenge to society. Living organisms can produce and pattern an extraordinarily wide range of different molecules in a sustainable way. These natural systems offer an abundant source of inspiration for the development of new environmentally friendly materials production techniques. In this paper, we describe the first steps toward the 3-dimensional printing of bacterial cultures for materials production and patterning. This methodology combines the capability of bacteria to form new materials with the reproducibility and tailored approach of 3D printing systems. For this purpose, a commercial 3D printer was modified for bacterial systems, and new alginate-based bioink chemistry was developed. Printing temperature, printhead speed, and bioink extrusion rate were all adapted and customized to maximize bacterial health and spatial resolution of printed structures. Our combination of 3D printing technology with biological systems enables a sustainable approach for the production of numerous new materials. PMID:28225616

A Straightforward Approach for 3D Bacterial Printing.

PubMed

Lehner, Benjamin A E; Schmieden, Dominik T; Meyer, Anne S

2017-07-21

Sustainable and personally tailored materials production is an emerging challenge to society. Living organisms can produce and pattern an extraordinarily wide range of different molecules in a sustainable way. These natural systems offer an abundant source of inspiration for the development of new environmentally friendly materials production techniques. In this paper, we describe the first steps toward the 3-dimensional printing of bacterial cultures for materials production and patterning. This methodology combines the capability of bacteria to form new materials with the reproducibility and tailored approach of 3D printing systems. For this purpose, a commercial 3D printer was modified for bacterial systems, and new alginate-based bioink chemistry was developed. Printing temperature, printhead speed, and bioink extrusion rate were all adapted and customized to maximize bacterial health and spatial resolution of printed structures. Our combination of 3D printing technology with biological systems enables a sustainable approach for the production of numerous new materials.

Efficacy and pharmacokinetics of a modified acid-labile docetaxel-PRINT(®) nanoparticle formulation against non-small-cell lung cancer brain metastases.

PubMed

Sambade, Maria; Deal, Allison; Schorzman, Allison; Luft, J Christopher; Bowerman, Charles; Chu, Kevin; Karginova, Olga; Swearingen, Amanda Van; Zamboni, William; DeSimone, Joseph; Anders, Carey K

2016-08-01

Particle Replication in Nonwetting Templates (PRINT(®)) PLGA nanoparticles of docetaxel and acid-labile C2-dimethyl-Si-Docetaxel were evaluated with small molecule docetaxel as treatments for non-small-cell lung cancer brain metastases. Pharmacokinetics, survival, tumor growth and mice weight change were efficacy measures against intracranial A549 tumors in nude mice. Treatments were administered by intravenous injection. Intracranial tumor concentrations of PRINT-docetaxel and PRINT-C2-docetaxel were 13- and sevenfold greater, respectively, than SM-docetaxel. C2-docetaxel conversion to docetaxel was threefold higher in intracranial tumor as compared with nontumor tissues. PRINT-C2-docetaxel increased median survival by 35% with less toxicity as compared with other treatments. The decreased toxicity of the PRINT-C2-docetaxel improved treatment efficacy against non-small-cell lung cancer brain metastasis.

Evaluating the impact of an educational intervention to increase CRC screening rates in the African American community: a preliminary study.

PubMed

Philip, Errol J; DuHamel, Katherine; Jandorf, Lina

2010-10-01

Despite the acknowledged importance of colorectal cancer (CRC) screening and its proven prognostic benefit, African American men and women simultaneously possess the highest rates of CRC-related incidence and mortality (Swan et al. in Cancer 97(6):1528-1540, 2003) and lowest screening rates in the United States (Polite et al. in Med Clin N Am 89(4):771-793, 2005). Effective, targeted interventions that promote CRC screening for this community are therefore critical. The current study evaluated the impact of a print-based educational intervention on screening behavior and associated patient-based factors, including cancer-related knowledge, fatalism, worry, and decisional balance (pros-cons). One hundred and eighteen individuals (mean age = 56.08, SD = 5.58) who had not undergone screening were recruited from two health clinics in New York City. Each participant received educational print materials regarding the need for screening, the process of undergoing screening, and the benefits of regular CRC screening. One in four individuals had undergone post-intervention screening at a three-month follow-up. Whereas all participants reported a decrease in cancer-related worry (p < .05), it was a decrease in fatalism (p < .05) and an increase in decisional balance (p < .05) that was associated with post-intervention screening behavior. These preliminary results suggest that fatalistic beliefs and an individual's assessment of the benefits and barriers of screening may be critical in the decision to undergo CRC screening. Future interventions to increase CRC-screening rates for this community may be improved by focusing on these patient-based factors.

Screening of female family members of von Willebrand disease patients: utility of a modified screening tool in a high-risk population.

PubMed

Faiz, A S; Kaveney, A; Guo, S; Murphy, S; Philipp, C S

2017-09-01

Family members of Von Willebrand disease (VWD) patients may have low levels of VWF without major bleeding episodes and often remain undiagnosed. The purpose of this study was to assess the utility of a modified Screening Tool in identifying previously untested reproductive age female family members of VWD patients for haemostatic evaluation. Ninety-four reproductive age women including 41 previously untested family members of VWD patients, 26 previously diagnosed VWD patients and 27 healthy controls were administered a modified Screening Tool and had blood drawn for CBC, ferritin, and VWF testing. Participants completed a pictorial blood assessment chart (PBAC) with menses. The modified Screening Tool was positive in 32% family members, 77% VWD patients, and 19% controls (P < 0.001). Combined with low ferritin, the modified Screening Tool was positive in 66% family members, 92% VWD patients, and 44% controls (P = 0.001). In family members, incorporating low ferritin with the modified Screening Tool resulted in a sensitivity of 86% (95% CI, 42-100) and negative predictive value of 93% (95% CI, 66-100). In the control group, NPV was between 92% and 95% for the modified Screening Tool and also for the modified Screening Tool combined with low ferritin or a positive PBAC. These data in a racially diverse population suggest the usefulness of a simple, easy to administer modified Screening Tool. In conjunction with ferritin it could be used in a primary care setting to stratify reproductive age women with a family history of VWD for haemostatic evaluation. © 2017 John Wiley & Sons Ltd.

Feasibility and Characterization of Common and Exotic Filaments for Use in 3D Printed Terahertz Devices

NASA Astrophysics Data System (ADS)

Squires, A. D.; Lewis, R. A.

2018-06-01

Recent years have seen an influx of applications utilizing 3D printed devices in the terahertz regime. The simplest, and perhaps most versatile, modality allowing this is Fused Deposition Modelling. In this work, a holistic analysis of the terahertz optical, mechanical and printing properties of 17 common and exotic 3D printer filaments used in Fused Deposition Modelling is performed. High impact polystyrene is found to be the best filament, with a useable frequency range of 0.1-1.3 THz, while remaining easily printed. Nylon, polylactic acid and polyvinyl alcohol give the least desirable terahertz response, satisfactory only below 0.5 THz. Interestingly, most modified filaments aimed at increasing mechanical properties and ease of printing do so without compromising the useable terahertz optical window.

Review of the Potential of the Ni/Cu Plating Technique for Crystalline Silicon Solar Cells

PubMed Central

Rehman, Atteq ur; Lee, Soo Hong

2014-01-01

Developing a better method for the metallization of silicon solar cells is integral part of realizing superior efficiency. Currently, contact realization using screen printing is the leading technology in the silicon based photovoltaic industry, as it is simple and fast. However, the problem with metallization of this kind is that it has a lower aspect ratio and higher contact resistance, which limits solar cell efficiency. The mounting cost of silver pastes and decreasing silicon wafer thicknesses encourages silicon solar cell manufacturers to develop fresh metallization techniques involving a lower quantity of silver usage and not relying pressing process of screen printing. In recent times nickel/copper (Ni/Cu) based metal plating has emerged as a metallization method that may solve these issues. This paper offers a detailed review and understanding of a Ni/Cu based plating technique for silicon solar cells. The formation of a Ni seed layer by adopting various deposition techniques and a Cu conducting layer using a light induced plating (LIP) process are appraised. Unlike screen-printed metallization, a step involving patterning is crucial for opening the masking layer. Consequently, experimental procedures involving patterning methods are also explicated. Lastly, the issues of adhesion, back ground plating, process complexity and reliability for industrial applications are also addressed. PMID:28788516

Review of the Potential of the Ni/Cu Plating Technique for Crystalline Silicon Solar Cells.

PubMed

Rehman, Atteq Ur; Lee, Soo Hong

2014-02-18

Developing a better method for the metallization of silicon solar cells is integral part of realizing superior efficiency. Currently, contact realization using screen printing is the leading technology in the silicon based photovoltaic industry, as it is simple and fast. However, the problem with metallization of this kind is that it has a lower aspect ratio and higher contact resistance, which limits solar cell efficiency. The mounting cost of silver pastes and decreasing silicon wafer thicknesses encourages silicon solar cell manufacturers to develop fresh metallization techniques involving a lower quantity of silver usage and not relying pressing process of screen printing. In recent times nickel/copper (Ni/Cu) based metal plating has emerged as a metallization method that may solve these issues. This paper offers a detailed review and understanding of a Ni/Cu based plating technique for silicon solar cells. The formation of a Ni seed layer by adopting various deposition techniques and a Cu conducting layer using a light induced plating (LIP) process are appraised. Unlike screen-printed metallization, a step involving patterning is crucial for opening the masking layer. Consequently, experimental procedures involving patterning methods are also explicated. Lastly, the issues of adhesion, back ground plating, process complexity and reliability for industrial applications are also addressed.

Photosensitive space charge limited current in screen printed CdTe thin films

NASA Astrophysics Data System (ADS)

Vyas, C. U.; Pataniya, Pratik; Zankat, Chetan K.; Patel, Alkesh B.; Pathak, V. M.; Patel, K. D.; Solanki, G. K.

2018-05-01

Group II-VI Compounds have emerged out as most suitable in the class of photo sensitive material. They represent a strong position in terms of their applications in the field of detectors as well as photo voltaic devices. Cadmium telluride is the prime member of this Group, because of high acceptance of this material as active component in opto-electronic devices. In this paper we report preparation and characterization of CdTe thin films by using a most economical screen printing technique in association with sintering at 510°C temperature. Surface morphology and smoothness are prime parameters of any deposited to be used as an active region of devices. Thus, we studied of the screen printed thin film by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM) for this purpose. However, growth processes induced intrinsic defects in fabricated films work as charge traps and affect the conduction process significantly. So the conduction mechanism of deposited CdTe thin film is studied under dark as well as illuminated conditions. It is found that the deposited films showed the space charge limited conduction (SCLC) mechanism and hence various parameters of space charge limited conduction (SCLC) of CdTe film were evaluated and discussed and the photo responsive resistance is also presented in this paper.

High-efficiency screen-printed belt co-fired solar cells on cast multicrystalline silicon

NASA Astrophysics Data System (ADS)

Upadhyaya, Ajay; Sheoran, Manav; Rohatgi, Ajeet

2005-01-01

High-efficiency 4cm2 untextured screen-printed solar cells were achieved on cast multicrystalline silicon. These cells were fabricated using a simple manufacturable process involving POCl3 diffusion for emitter, PECVD SiNx:H deposition for a single-layer antireflection coating and rapid co-firing of Ag grid, Al backcontact, and Al-BSF in a belt furnace. An optimized process sequence contributed to effective impurity gettering and defect passivation, resulting in high average bulk lifetimes in the range of 100-250 μs after the cell processing. The contact firing contributed to good ohmic contacts with low series resistance of <1Ωcm2, low backsurface recombination velocity of <500cm/s, and high fill factors of ˜0.78. These parameters resulted in 16.9% and 16.8% efficient untextured screen-printed cells with a single layer AR coating on heat exchanger method (HEM) and Baysix mc-Si. The identical process applied to the untextured float zone wafers gave an efficiency of 17.2%. The same optimized co-firing cycle, when applied to HEM mc-Si wafers with starting lifetimes varying over a wide range of 4-70 μs, resulted in cell efficiencies in the range of 16.5%-17%.

Simultaneous determination of hydroquinone, catechol and resorcinol by voltammetry using graphene screen-printed electrodes and partial least squares calibration.

PubMed

Aragó, Miriam; Ariño, Cristina; Dago, Àngela; Díaz-Cruz, José Manuel; Esteban, Miquel

2016-11-01

Catechol (CC), resorcinol (RC) and hydroquinone (HQ) are dihydroxybenzene isomers that usually coexist in different samples and can be determined using voltammetric techniques taking profit of their fast response, high sensitivity and selectivity, cheap instrumentation, simple and timesaving operation modes. However, a strong overlapping of CC and HQ signals is observed hindering their accurate analysis. In the present work, the combination of differential pulse voltammetry with graphene screen-printed electrodes (allowing detection limits of 2.7, 1.7 and 2.4µmolL(-1) for HQ, CC and RC respectively) and the data analysis by partial least squares calibration (giving root mean square errors of prediction, RMSEP values, of 2.6, 4.1 and 2.3 for HQ, CC and RC respectively) has been proposed as a powerful tool for the quantification of mixtures of these dihydroxybenzene isomers. The commercial availability of the screen-printed devices and the low cost and simplicity of the analysis suggest that the proposed method can be a valuable alternative to chromatographic and electrophoretic methods for the considered species. The method has been applied to the analysis of these isomers in spiked tap water. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface processing and ageing behavior of silk fabrics treated with atmospheric-pressure plasma for pigment-based ink-jet printing

NASA Astrophysics Data System (ADS)

Zhang, Chunming; Wang, Libing; Yu, Miao; Qu, Lijun; Men, Yajing; Zhang, Xiangwu

2018-03-01

Pigment inkjet printing has highlighted the advantages of cost-effective, short production cycle and environment-friendly. However, patterns directly printed with pigment inks usually have low color yields and blurry images which are caused by bleeding phenomenon. This work presents an atmospheric-pressure plasma method for improving the pigment-based ink-jet printing performance of silk fabrics. The effects of surface changes induced are discussed, with data derived from morphological study by atomic force microscopy (AFM), chemical analysis using X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Ink-jet printing experiments were conducted to study the influence of measured changes on anti-bleeding property and color strength of treated and original samples. The ageing experiment indicates that the modified silk fabrics should be printed within 24 h after plasma processing for maximum color yields. This study explores an effective approach for the atmospheric-pressure plasma, which can provide its significant use in improving the surface properties and ink-jet printing performance of fabrics.

Correlative microscopy including CLSM and SEM to improve high-speed, high-resolution laser-engraved print and embossing forms

NASA Astrophysics Data System (ADS)

Bohrer, Markus; Schweitzer, Michael; Nirnberger, Robert; Weinberger, Bernhard

2015-10-01

The industrial market for processing large-scale films has seen dramatic changes since the 1980s and has almost completely been replaced by lasers and digital processes. A commonly used technology for engraving screens, print and embossing forms in the printing industry, well known since then, is the use of RF-excited CO2 lasers with a beam power up to about 1 kW, modulated in accordance to the pattern to be engraved. Future needs for high-security printing (banknotes, security papers, passports, etc.) will require laser engraving of at least half a million or even more structured elements with a depth from some μm up to 500 μm. Industry now wants photorealistic pictures in packaging design, which requires a similar performance. To ensure 'trusted pulses' from the digital process to the print result the use of correlative microscopy (CLSM and SEM) is demonstrated as a complete chain for a correlative print process in this paper.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Very, F.; Rosenkrantz, E.; Combette, P.

The development of advanced instrumentation for in-pile experiments in Material Testing Reactor constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. An acoustic method for fission gas release detection was tested with success during a first experiment called REMORA 3 in 2010 and 2011, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. This experiment was lead at OSIRIS reactor (CEA Saclay, France). The maximal temperature on the sensor during the irradiation was about 150 deg. C. In this paper we present a thick film transducer produce bymore » screen printing process. The screen printing of piezoelectric offers a wide range of possible applications for the development of acoustic sensors and piezoelectric structure for measurements in high temperature environment. We firstly produced a Lead Zirconate Titanate (PZT) based paste composed of Pz27 powder from Ferroperm, CF7575 glass, and organic solvent ESL 400. Likewise a Bismuth Titanate based paste synthesized in our laboratory was produced. With these inks we produced thick film up to 130 μm by screen printing process. Material properties characterizations of these thick-film resonators are essential for device design and applications. The piezoelectric coefficients d33 and pyro-electric P(T) coefficient are investigated. The highest P(T) and d33 are respectively 80 μC.m{sup -2}.K{sup -1} and 130 μC.N{sup -1} for the PZT transducer -which validates the fabrication process-. In view of the development of this transducer oriented for high temperature and irradiation environment, we investigated the electrical properties of the transducers for different ranges of frequencies and temperature - from 20 Hz up to 40 MHz between 30 and 400 deg. C. We highlight the evolution of the impedance response and piezoelectric parameters of screen printed piezoelectric structures on alumina. Shortly an irradiation will be realized in order to investigate their reliability towards neutron fluence. (authors)« less

Effect of screen printing type on transparent TiO2 layer as the working electrode of dye sensitized solar cell (DSSC) for solar windows applications

NASA Astrophysics Data System (ADS)

Nurosyid, F.; Furqoni, L.; Supriyanto, A.; Suryana, R.

2016-11-01

The working electrode based on semiconductor TiO2 DSSC has been fabricated by screen printing method. This study aim is to determine the effect of the screen type on TiO2 layer as the working electrode of DSSC. Screen used for deposition of TiO2 has the types of; T- 49, T-55 and T-61. TiO2 layer was sintered at temperature of 500°C. DSSC structure was composed of semiconductor TiO2 adsorbed dye, an electrolyte solution and a platinum counter electrode. TiO2 layer thickness was characterized by Scanning Electron Microscopy (SEM), while the absorbance was characterized using UV-Vis spectrophotometer and the electrical properties of DSSC were characterized by Keithley I-V measurement. TiO2 layer fabricated by screen T-49 had the biggest thickness that was 3.2 ± 0.3 μm and the highest UV-Vis absorbance wave at the peak wavelength of 315 nm with the absorbance value was 1.7. The I-V characterization showed that the sample fabricated by screen T-49 obtained the greatest efficiency that was 1.0 × 10-1%

Structural and congenital heart disease interventions: the role of three-dimensional printing.

PubMed

Meier, L M; Meineri, M; Qua Hiansen, J; Horlick, E M

2017-02-01

Advances in catheter-based interventions in structural and congenital heart disease have mandated an increased demand for three-dimensional (3D) visualisation of complex cardiac anatomy. Despite progress in 3D imaging modalities, the pre- and periprocedural visualisation of spatial anatomy is relegated to two-dimensional flat screen representations. 3D printing is an evolving technology based on the concept of additive manufacturing, where computerised digital surface renders are converted into physical models. Printed models replicate complex structures in tangible forms that cardiovascular physicians and surgeons can use for education, preprocedural planning and device testing. In this review we discuss the different steps of the 3D printing process, which include image acquisition, segmentation, printing methods and materials. We also examine the expanded applications of 3D printing in the catheter-based treatment of adult patients with structural and congenital heart disease while highlighting the current limitations of this technology in terms of segmentation, model accuracy and dynamic capabilities. Furthermore, we provide information on the resources needed to establish a hospital-based 3D printing laboratory.

Target-responsive aptamer release from manganese dioxide nanosheets for electrochemical sensing of cocaine with target recycling amplification.

PubMed

Chen, Zongbao; Lu, Minghua

2016-11-01

A novel electrochemical sensing platform based on manganese dioxide (MnO2) nanosheets was developed for sensitive screening of target cocaine with the signal amplification. Ferrocene-labeled cocaine aptamers were initially immobilized onto MnO2 nanosheets-modified screen-printed carbon electrode because of π-stacking interaction between nucleobases and nanosheets. The immobilized ferrocene-aptamer activated the electrical contact with the electrode, thereby resulting in the sensor circuit to switch on. Upon target cocaine introduction, the analyte reacted with the aptamer and caused the dissociation of ferrocene-aptamer from the electrode, thus giving rise to the detection circuit to switch off. The released aptamer was cleaved by DNase I with target recycling. Under optimal conditions, the decreasing percentage of the electronic signal relative to background current increased with the increasing cocaine concentration in the dynamic range of 0.1-20nM, and the detection limit was 32pM. The reproducibility, selectivity and method accuracy were acceptable. Importantly, this concept offers promise for rapid, simple, and cost-effective analysis of cocaine biological samples without the needs of sample separation and multiple washing steps. Copyright © 2016 Elsevier B.V. All rights reserved.

Living Cell Microarrays: An Overview of Concepts

PubMed Central

Jonczyk, Rebecca; Kurth, Tracy; Lavrentieva, Antonina; Walter, Johanna-Gabriela; Scheper, Thomas; Stahl, Frank

2016-01-01

Living cell microarrays are a highly efficient cellular screening system. Due to the low number of cells required per spot, cell microarrays enable the use of primary and stem cells and provide resolution close to the single-cell level. Apart from a variety of conventional static designs, microfluidic microarray systems have also been established. An alternative format is a microarray consisting of three-dimensional cell constructs ranging from cell spheroids to cells encapsulated in hydrogel. These systems provide an in vivo-like microenvironment and are preferably used for the investigation of cellular physiology, cytotoxicity, and drug screening. Thus, many different high-tech microarray platforms are currently available. Disadvantages of many systems include their high cost, the requirement of specialized equipment for their manufacture, and the poor comparability of results between different platforms. In this article, we provide an overview of static, microfluidic, and 3D cell microarrays. In addition, we describe a simple method for the printing of living cell microarrays on modified microscope glass slides using standard DNA microarray equipment available in most laboratories. Applications in research and diagnostics are discussed, e.g., the selective and sensitive detection of biomarkers. Finally, we highlight current limitations and the future prospects of living cell microarrays. PMID:27600077

Sculplexity: Sculptures of Complexity using 3D printing

NASA Astrophysics Data System (ADS)

Reiss, D. S.; Price, J. J.; Evans, T. S.

2013-11-01

We show how to convert models of complex systems such as 2D cellular automata into a 3D printed object. Our method takes into account the limitations inherent to 3D printing processes and materials. Our approach automates the greater part of this task, bypassing the use of CAD software and the need for manual design. As a proof of concept, a physical object representing a modified forest fire model was successfully printed. Automated conversion methods similar to the ones developed here can be used to create objects for research, for demonstration and teaching, for outreach, or simply for aesthetic pleasure. As our outputs can be touched, they may be particularly useful for those with visual disabilities.

Graphene-Decorated Nanocomposites for Printable Electrodes in Thin Wafer Devices

NASA Astrophysics Data System (ADS)

Bakhshizadeh, N.; Sivoththaman, S.

2017-12-01

Printable electrodes that induce less stress and require lower curing temperatures compared to traditional screen-printed metal pastes are needed in thin wafer devices such as future solar cells, and in flexible electronics. The synthesis of nanocomposites by incorporating graphene nanopowders as well as silver nanowires into epoxy-based electrically conductive adhesives (ECA) is examined to improve electrical conductivity and to develop alternate printable electrode materials that induce less stress on the wafer. For the synthesized graphene and Ag nanowire-decorated ECA nanocomposites, the curing kinetics were studied by dynamic and isothermal differential scanning calorimetry measurements. Thermogravimetric analysis on ECA, ECA-AG and ECA/graphene nanopowder nanocomposites showed that the temperatures for onset of decomposition are higher than their corresponding glass transition temperature ( T g) indicating an excellent thermal resistance. Printed ECA/Ag nanowire nanocomposites showed 90% higher electrical conductivity than ECA films, whereas the ECA/graphene nanocomposites increased the conductivity by over two orders of magnitude. Scanning electron microscopy results also revealed the effect of fillers morphology on the conductivity improvement and current transfer mechanisms in nanocomposites. Residual stress analysis performed on Si wafers showed that the ECA and nanocomposite printed wafers are subjected to much lower stress compared to those printed with metallic pastes. The observed parameters of low curing temperature, good thermal resistance, reasonably high conductivity, and low residual stress in the ECA/graphene nanocomposite makes this material a promising alternative in screen-printed electrode formation in thin substrates.

FRED user's manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shilling, J.

1984-02-01

FRED, the friendly editor, is a screen-based structured editor. This manual is intended to serve the needs of a wide range of users of the FRED text editor. Most users will find it sufficient to read the introductory material in section 2, supplemented with the full command set description in section 3. Advanced users may wish to change the keystroke sequences which invoke editor commands. Section 4 describes how to change key bindings and how to define command macros. Some users may need to modify a language description or create an entirely new language description for use with FRED. Sectionmore » 5 describes the format of the language descriptions used by the editor, and describes how to construct a language grammar. Section 6 describes known portability problems of the FRED editor and should concern only system installation personnel. The editor points out syntax errors in the file being edited and does automatic pretty printing.« less

Disposable electrochemical immunosensor for Brettanomyces bruxellensis based on nanogold-reduced graphene oxide hybrid nanomaterial.

PubMed

Borisova, Boryana; Villalonga, María L; Arévalo-Villena, María; Boujakhrout, Abderrahmane; Sánchez, Alfredo; Parrado, Concepción; Pingarrón, José M; Briones-Pérez, Ana; Villalonga, Reynaldo

2017-09-01

The assembly of a novel disposable amperometric immunosensor for the detection of the red wine spoilage yeast Brettanomyces bruxellensis is reported. The nanostructured sensing interface was prepared by first coating carbon screen printed electrodes with a gold nanoparticles-reduced graphene oxide hybrid nanomaterial, which was then modified with 3-mercaptopropionic acid to further immobilize specific antibodies for B. bruxellensis via a carbodiimide-coupling reaction. The functionalized electrode allowed the amperometric detection of B. bruxellensis in buffered solutions and red wine samples in the range of 10-10 6  CFU/mL and 10 2 -10 6  CFU/mL, with low detection limits of 8 CFU/mL and 56 CFU/mL, respectively. The electrochemical immunosensor also exhibited high reproducibility, selectivity, and storage stability. Graphical abstract A novel disposable electrochemical immunosensor for the detection of the red wine spoilage yeast B. bruxellensis.

Acetylcholinesterase inhibition-based biosensor for aluminum(III) chronoamperometric determination in aqueous media.

PubMed

Barquero-Quirós, Miriam; Domínguez-Renedo, Olga; Alonso-Lomillo, Maria Asunción; Arcos-Martínez, María Julia

2014-05-07

A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water . The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties.

Acetylcholinesterase Inhibition-Based Biosensor for Aluminum(III) Chronoamperometric Determination in Aqueous Media

PubMed Central

Barquero-Quirós, Miriam; Domínguez-Renedo, Olga; Alonso-Lomillo, Maria Asunción; Arcos-Martínez, María Julia

2014-01-01

A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water. The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties. PMID:24811076

SPR and electrochemical analyses of interactions between CYP3A4 or 3A5 and cytochrome b5

NASA Astrophysics Data System (ADS)

Gnedenko, O. V.; Yablokov, E. O.; Usanov, S. A.; Mukha, D. V.; Sergeev, G. V.; Bulko, T. V.; Kuzikov, A. V.; Moskaleva, N. E.; Shumyantseva, V. V.; Ivanov, A. S.; Archakov, A. I.

2014-02-01

The combination of SPR biosensor with electrochemical analysis was used for the study of protein-protein interaction between cytochromes CYP3A4 or 3А5 and cytochromes b5: the microsomal, mitochondrial forms of this protein, and 2 ≪chimeric≫ proteins. Kinetic constants of CYP3A4 and CYP3А5 complex formation with cytochromes b5 were determined by the SPR biosensor. Essential distinction between CYP3A4 and CYP3A5 was observed upon their interactions with mitochondrial cytochrome b5. The electrochemical analysis of CYP3A4, CYP3A5, and cytochromes b5 immobilized on screen printed graphite electrodes modified with membranous matrix revealed that these proteins have very close reduction potentials -0.435 to -0.350 V (vs. Ag/AgCl).

Printed organo-functionalized graphene for biosensing applications.

PubMed

Wisitsoraat, A; Mensing, J Ph; Karuwan, C; Sriprachuabwong, C; Jaruwongrungsee, K; Phokharatkul, D; Daniels, T M; Liewhiran, C; Tuantranont, A

2017-01-15

Graphene is a highly promising material for biosensors due to its excellent physical and chemical properties which facilitate electron transfer between the active locales of enzymes or other biomaterials and a transducer surface. Printing technology has recently emerged as a low-cost and practical method for fabrication of flexible and disposable electronics devices. The combination of these technologies is promising for the production and commercialization of low cost sensors. In this review, recent developments in organo-functionalized graphene and printed biosensor technologies are comprehensively covered. Firstly, various methods for printing graphene-based fluids on different substrates are discussed. Secondly, different graphene-based ink materials and preparation methods are described. Lastly, biosensing performances of printed or printable graphene-based electrochemical and field effect transistor sensors for some important analytes are elaborated. The reported printed graphene based sensors exhibit promising properties with good reliability suitable for commercial applications. Among most reports, only a few printed graphene-based biosensors including screen-printed oxidase-functionalized graphene biosensor have been demonstrated. The technology is still at early stage but rapidly growing and will earn great attention in the near future due to increasing demand of low-cost and disposable biosensors. Copyright © 2016 Elsevier B.V. All rights reserved.

Using screening level environmental life cycle assessment to aid decision making: A case study of a college annual report

EPA Science Inventory

Purpose – In this study we compare the life cycle environmental impacts of the University of Cincinnati College of Engineering and Applied Sciences’ current printed annual report to a version distributed via the Internet. This case study demonstrates how a screening level life cy...

Equivalence of Screen versus Print Reading Comprehension Depends on Task Complexity and Proficiency

ERIC Educational Resources Information Center

Lenhard, Wolfgang; Schroeders, Ulrich; Lenhard, Alexandra

2017-01-01

As reading and reading assessment become increasingly implemented on electronic devices, the question arises whether reading on screen is comparable with reading on paper. To examine potential differences, we studied reading processes on different proficiency and complexity levels. Specifically, we used data from the standardization sample of the…

15. Photographic copy of construction drawing DP28827 (from record group ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. Photographic copy of construction drawing DP-28827 (from record group of Civil Engineering, Hill Air Force Base, Utah). Dec. 16, 1940. 8x10 negative and print. STANDARD BLACK POWDER SCREENING BUILDING. ROOF FRAMING PLAN & DETAILS. - Ogden Arsenal, Black Powder Screening Building, 7745 Navajo Way, Layton, Davis County, UT

Performance, stability and operation voltage optimization of screen-printed aqueous supercapacitors

PubMed Central

Lehtimäki, Suvi; Railanmaa, Anna; Keskinen, Jari; Kujala, Manu; Tuukkanen, Sampo; Lupo, Donald

2017-01-01

Harvesting micropower energy from the ambient environment requires an intermediate energy storage, for which printed aqueous supercapacitors are well suited due to their low cost and environmental friendliness. In this work, a systematic study of a large set of devices is used to investigate the effect of process variability and operating voltage on the performance and stability of screen printed aqueous supercapacitors. The current collectors and active layers are printed with graphite and activated carbon inks, respectively, and aqueous NaCl used as the electrolyte. The devices are characterized through galvanostatic discharge measurements for quantitative determination of capacitance and equivalent series resistance (ESR), as well as impedance spectroscopy for a detailed study of the factors contributing to ESR. The capacitances are 200–360 mF and the ESRs 7.9–12.7 Ω, depending on the layer thicknesses. The ESR is found to be dominated by the resistance of the graphite current collectors and is compatible with applications in low-power distributed electronics. The effects of different operating voltages on the capacitance, leakage and aging rate of the supercapacitors are tested, and 1.0 V found to be the optimal choice for using the devices in energy harvesting applications. PMID:28382962

Efficacy of print advertising for a bipolar disorder study.

PubMed

Roy, Sumeet; Patel, Shilpa; Sheehan, Kathy Harnett; Janavs, Juris; Sheehan, David

2008-01-01

Using quality and quantity of responses, this study evaluated the efficacy of advertising in print media for a bipolar disorder clinical trial. We analyzed the corresponding quantity of calls generated and the cost per patient yield at each of the standard study milestones, spending on print advertising. Quality of calls was based on the attrition rates at each of the study stages. Five hundred and twenty-six calls were received over a 28-month period (February 2004 to June 2006). The largest number of calls were received early in the week (Monday, 25.6%; Tuesday, 23.5%; Wednesday, 18.8%), corresponding with increased advertisements toward the end of the previous week. From the total calls received, 17.14% were eligible for a screening visit, 10.28% were randomized, 9.14% were evaluable, and 7% completed the 8-week study. Sixty percent of the subjects who attended the screening visit were randomized and 68.5% of the randomized subjects completed the study. The yield from phone calls responding to print advertising for a bipolar disorder study was 7%, costing $1,330 per evaluable subject and $1,725 per completed subject. These figures may be useful benchmarks in recruitment planning and budgeting for participants in clinical trials on bipolar disorder.

Reading Habits, Perceptual Learning, and Recognition of Printed Words

ERIC Educational Resources Information Center

Nazir, Tatjana A.; Ben-Boutayab, Nadia; Decoppet, Nathalie; Deutsch, Avital; Frost, Ram

2004-01-01

The present work aims at demonstrating that visual training associated with the act of reading modifies the way we perceive printed words. As reading does not train all parts of the retina in the same way but favors regions on the side in the direction of scanning, visual word recognition should be better at retinal locations that are frequently…

Fabrication of controlled-release budesonide tablets via desktop (FDM) 3D printing.

PubMed

Goyanes, Alvaro; Chang, Hanah; Sedough, Daniel; Hatton, Grace B; Wang, Jie; Buanz, Asma; Gaisford, Simon; Basit, Abdul W

2015-12-30

The aim of this work was to explore the feasibility of using fused deposition modelling (FDM) 3D printing (3DP) technology with hot melt extrusion (HME) and fluid bed coating to fabricate modified-release budesonide dosage forms. Budesonide was sucessfully loaded into polyvinyl alcohol filaments using HME. The filaments were engineered into capsule-shaped tablets (caplets) containing 9mg budesonide using a FDM 3D printer; the caplets were then overcoated with a layer of enteric polymer. The final printed formulation was tested in a dynamic dissolution bicarbonate buffer system, and two commercial budesonide products, Cortiment® (Uceris®) and Entocort®, were also investigated for comparison. Budesonide release from the Entocort® formulation was rapid in conditions of the upper small intestine while release from the Cortiment® product was more delayed and very slow. In contrast, the new 3D printed caplet formulation started to release in the mid-small intestine but release then continued in a sustained manner throughout the distal intestine and colon. This work has demonstrated the potential of combining FDM 3DP with established pharmaceutical processes, including HME and film coating, to fabricate modified release oral dosage forms. Copyright © 2015. Published by Elsevier B.V.

Toward continuous glucose monitoring with planar modified biosensors and microdialysis. Study of temperature, oxygen dependence and in vivo experiment.

PubMed

Ricci, Francesco; Caprio, Felice; Poscia, Alessandro; Valgimigli, Francesco; Messeri, Dimitri; Lepori, Elena; Dall'Oglio, Giorgio; Palleschi, Giuseppe; Moscone, Danila

2007-04-15

Glucose biosensors based on the use of planar screen-printed electrodes modified with an electrochemical mediator and with glucose oxidase have been optimised for their application in the continuous glucose monitoring in diabetic patients. A full study of their operative stability and temperature dependence has been accomplished, thus giving useful information for in vivo applications. The effect of dissolved oxygen concentration in the working solution was also studied in order to evaluate its effect on the linearity of the sensors. Glucose monitoring performed with serum samples was performed to evaluate the effect of matrix components on operative stability and demonstrated an efficient behaviour for 72 h of continuous monitoring. Finally, these studies led to a sensor capable of detecting glucose at concentrations as low as 0.04 mM and with a good linearity up to 2.0 mM (at 37 degrees C) with an operative stability of ca. 72 h, thus demonstrating the possible application of these sensors for continuous glucose monitoring in conjunction with a microdialysis probe. Moreover, preliminary in vivo experiments for ca. 20 h have demonstrated the feasibility of this system.

Integrated amperometric affinity biosensors using Co2+-tetradentate nitrilotriacetic acid modified disposable carbon electrodes: application to the determination of β-lactam antibiotics.

PubMed

Conzuelo, Felipe; Gamella, María; Campuzano, Susana; Martínez-Ruiz, Paloma; Esteban-Torres, María; de las Rivas, Blanca; Reviejo, A Julio; Muñoz, Rosario; Pingarrón, José M

2013-03-19

A novel strategy for the construction of disposable amperometric affinity biosensors is described in this work. The approach uses a recombinant bacterial penicillin binding protein (PBP) tagged by an N-terminal hexahistidine tail which was immobilized onto Co(2+)-tetradentate nitrilotriacetic acid (NTA)-modified screen-printed carbon electrodes (SPCEs). The biosensor was employed for the specific detection and quantification of β-lactam antibiotics residues in milk, which was accomplished by means of a direct competitive assay using a tracer with horseradish peroxidase (HRP) for the enzymatic labeling. The amperometric response measured at -0.20 V versus the Ag pseudoreference electrode of the SPCE upon the addition of H2O2 in the presence of hydroquinone (HQ) as redox mediator was used as the transduction signal. The developed affinity sensor allowed limits of detection to be obtained in the low part-per-billion level for the antibiotics tested in untreated milk samples. Moreover, the biosensor exhibited a good selectivity against other antibiotics residues frequently detected in milk and dairy products. The analysis time was of approximately 30 min.

Highly sensitive electrochemical detection of cocaine on graphene/AuNP modified electrode via catalytic redox-recycling amplification.

PubMed

Jiang, Bingying; Wang, Min; Chen, Ying; Xie, Jiaqing; Xiang, Yun

2012-02-15

We demonstrated a new strategy for highly sensitive electrochemical detection of cocaine by using two engineered aptamers in connection to redox-recycling signal amplification. The graphene/AuNP nanocomposites were electrochemically deposited on a screen printed carbon electrode to enhance the electron transfers. The cocaine primary binding aptamers were self-assembled on the electrode surface through sulfur-Au interactions. The presence of the target cocaine and the biotin-modified secondary binding aptamers leads to the formation of sandwich complexes on the electrode surface. The streptavidin-conjugated alkaline phosphatases (ALPs) were used as labels to generate quantitative signals. The addition of the ALP substrate and the co-reactant NADH results in the formation of a redox cycle between the enzymatic product and the electrochemically oxidized species and the signal is thus significantly amplified. Because of the effective modification of the sensing surface and signal amplification, low nanomolar (1 nM) detection limit for cocaine is achieved. The proposed aptamer-based sandwich sensing approach for amplified detection of cocaine thus opens new opportunities for highly sensitive determination of other small molecules. Copyright © 2011 Elsevier B.V. All rights reserved.

Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds

PubMed Central

Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md. Rakibul

2016-01-01

A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075–10 µM and 10–55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days. PMID:27367738

Investigation of Proposed Process Sequence for the Array Automated Assembly Task, Phase 2. [low cost silicon solar array fabrication

NASA Technical Reports Server (NTRS)

Mardesich, N.; Garcia, A.; Bunyan, S.; Pepe, A.

1979-01-01

The technological readiness of the proposed process sequence was reviewed. Process steps evaluated include: (1) plasma etching to establish a standard surface; (2) forming junctions by diffusion from an N-type polymeric spray-on source; (3) forming a p+ back contact by firing a screen printed aluminum paste; (4) forming screen printed front contacts after cleaning the back aluminum and removing the diffusion oxide; (5) cleaning the junction by a laser scribe operation; (6) forming an antireflection coating by baking a polymeric spray-on film; (7) ultrasonically tin padding the cells; and (8) assembling cell strings into solar circuits using ethylene vinyl acetate as an encapsulant and laminating medium.

Injection-modulated polarity conversion by charge carrier density control via a self-assembled monolayer for all-solution-processed organic field-effect transistors

NASA Astrophysics Data System (ADS)

Roh, Jeongkyun; Lee, Taesoo; Kang, Chan-Mo; Kwak, Jeonghun; Lang, Philippe; Horowitz, Gilles; Kim, Hyeok; Lee, Changhee

2017-04-01

We demonstrated modulation of charge carrier densities in all-solution-processed organic field-effect transistors (OFETs) by modifying the injection properties with self-assembled monolayers (SAMs). The all-solution-processed OFETs based on an n-type polymer with inkjet-printed Ag electrodes were fabricated as a test platform, and the injection properties were modified by the SAMs. Two types of SAMs with different dipole direction, thiophenol (TP) and pentafluorobenzene thiol (PFBT) were employed, modifying the work function of the inkjet-printed Ag (4.9 eV) to 4.66 eV and 5.24 eV with TP and PFBT treatments, respectively. The charge carrier densities were controlled by the SAM treatment in both dominant and non-dominant carrier-channel regimes. This work demonstrates that control of the charge carrier densities can be efficiently achieved by modifying the injection property with SAM treatment; thus, this approach can achieve polarity conversion of the OFETs.

Selection of the optimum font type and size interface for on screen continuous reading by young adults: an ergonomic approach.

PubMed

Banerjee, Jayeeta; Bhattacharyya, Moushum

2011-12-01

There is a rapid shifting of media: from printed paper to computer screens. This transition is modifying the process of how we read and understand text. The efficiency of reading is dependent on how ergonomically the visual information is presented. Font types and size characteristics have been shown to affect reading. A detailed investigation of the effect of the font type and size on reading on computer screens has been carried out by using subjective, objective and physiological evaluation methods on young adults. A group of young participants volunteered for this study. Two types of fonts were used: Serif fonts (Times New Roman, Georgia, Courier New) and Sans serif fonts (Verdana, Arial, Tahoma). All fonts were presented in 10, 12 and 14 point sizes. This study used a 6 X 3 (font type X size) design matrix. Participants read 18 passages of approximately the same length and reading level on a computer monitor. Reading time, ranking and overall mental workload were measured. Eye movements were recorded by a binocular eye movement recorder. Reading time was minimum for Courier New l4 point. The participants' ranking was highest and mental workload was least for Verdana 14 point. The pupil diameter, fixation duration and gaze duration were least for Courier New 14 point. The present study recommends using 14 point sized fonts for reading on computer screen. Courier New is recommended for fast reading while for on screen presentation Verdana is recommended. The outcome of this study will help as a guideline to all the PC users, software developers, web page designers and computer industry as a whole.

Amperometric detection of catechol using tyrosinase modified electrodes enhanced by the layer-by-layer assembly of gold nanocubes and polyelectrolytes.

PubMed

Karim, Md Nurul; Lee, Ji Eun; Lee, Hye Jin

2014-11-15

A novel amperometric biosensor for catechol was developed using the layer-by-layer (LbL) self-assembly of positively charged hexadecyltrimethylammonium stabilized gold nanocubes (AuNCs), negatively charged poly(sodium 4-styrenesulfonate) and tyrosinase on a screen printed carbon electrode (SPCE). A carboxylic acid terminated alkanethiol assembled on electrochemically deposited Au nanoparticles on a SPCE was used as a platform for LbL assembly. Each SPCE sensor surface was terminated with tyrosinase and the electrocatalytic response due to the tyrosinase reaction with catechol was measured using cyclic voltammetry and square wave voltammetry (SWV). The effect of introducing AuNCs into the LbL assembly to further enhance the catechol detection performance was then investigated by comparing the SWV results to those from biosensors created using both the tyrosinase modified LbL assembly in the absence of NCs and the covalent attachment of tyrosinase. A wide dynamic range from 10nM to 80 µM of catechol with an excellent sensitivity of 13.72 A/M and a detection limit of 0.4 nM were both achieved alongside a good selectivity and reproducibility for the AuNC-modified electrodes. As a demonstration, the optimized biosensor design was applied to determine catechol concentrations in tea samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Military Research ColorDx and Printed Color Vision Tests.

PubMed

Almustanyir, Ali; Hovis, Jeffery K

2015-10-01

To determine the equivalence of the ColorDx Military Research version (mColorDx) test and three printed pseudoisochromatic tests (HRR, Ishihara, and PIPIC) for color vision testing. Participating in the study were 75 color-normals and 47 subjects with red-green color vision defects. Color vision was classified by an anomaloscope. The HRR (4(th) edition), Ishihara 38-plate edition, and PIPIC tests are printed color vision tests, whereas mColorDx test figures were displayed on a calibrated computer desktop monitor. All tests were repeated in about 1 wk. The kappa level of agreement (κ) values with the anomaloscope for screening for each test was 0.96 or greater. The values were statistically identical. Specificity for each test was at least 0.99 and sensitivity was at least 0.95. The repeatability of the screening sections for all tests was very good with κ values greater than 0.95. Deutans tended to miss the tritan screening plates on the HRR and mColorDx tests. The Spearman rank correlation coefficients between the severity of the defect and anomaloscope range was moderate with r = 0.45 for the mColorDx and r = 0.6 for the HRR. Both the mColorDx and HRR had perfect agreement with the anomaloscope in classifying the defects as either protan or deutan. The validity of the four tests for color vision screening was statistically identical; however, the HRR may be preferred because it had the highest sensitivity of 0.99, a specificity of 1.0, and a reasonable correlation between the severity rating of the defect and the anomaloscope range.

Low-cost printing of computerised tomography (CT) images where there is no dedicated CT camera.

PubMed

Tabari, Abdulkadir M

2007-01-01

Many developing countries still rely on conventional hard copy images to transfer information among physicians. We have developed a low-cost alternative method of printing computerised tomography (CT) scan images where there is no dedicated camera. A digital camera is used to photograph images from the CT scan screen monitor. The images are then transferred to a PC via a USB port, before being printed on glossy paper using an inkjet printer. The method can be applied to other imaging modalities like ultrasound and MRI and appears worthy of emulation elsewhere in the developing world where resources and technical expertise are scarce.

Effect of Patient Navigation on Breast Cancer Screening Among African American Medicare Beneficiaries: A Randomized Controlled Trial.

PubMed

Marshall, Jessie Kimbrough; Mbah, Olive M; Ford, Jean G; Phelan-Emrick, Darcy; Ahmed, Saifuddin; Bone, Lee; Wenzel, Jennifer; Shapiro, Gary R; Howerton, Mollie; Johnson, Lawrence; Brown, Qiana; Ewing, Altovise; Pollack, Craig Evan

2016-01-01

There is growing evidence that patient navigation improves breast cancer screening rates; however, there are limited efficacy studies of its effect among African American older adult women. To evaluate the effect of patient navigation on screening mammography among African American female Medicare beneficiaries in Baltimore, MD. The Cancer Prevention and Treatment Demonstration (CPTD), a multi-site study, was a randomized controlled trial conducted from April 2006 through December 2010. Community-based and clinical setting. The CPTD Screening Trial enrolled 1905 community-dwelling African American female Medicare beneficiaries who were ≥65 years of age and resided in Baltimore, MD. Participants were recruited from health clinics, community centers, health fairs, mailings using Medicare rosters, and phone calls. Participants were randomized to either: printed educational materials on cancer screening (control group) or printed educational materials + patient navigation services designed to help participants overcome barriers to cancer screening (intervention group). Self-reported receipt of mammography screening within 2 years of the end of the study. The median follow-up period for participants in this analysis was 17.8 months. In weighted multivariable logistic regression analyses, women in the intervention group had significantly higher odds of being up to date on mammography screening at the end of the follow-up period compared to women in the control group (odds ratio [OR] 2.26, 95 % confidence interval [CI]1.59-3.22). The effect of the intervention was stronger among women who were not up to date with mammography screening at enrollment (OR 3.63, 95 % CI 2.09-6.38). Patient navigation among urban African American Medicare beneficiaries increased self-reported mammography utilization. The results suggest that patient navigation for mammography screening should focus on women who are not up to date on their screening.

Impact of a Generalizable Reminder System on Colorectal Cancer Screening in Diverse Primary Care Practices

PubMed Central

Nease, Donald E.; Ruffin, Mack T.; Klinkman, Michael S.; Jimbo, Masahito; Braun, Thomas M.; Underwood, Jennifer M.

2015-01-01

Background Computerized reminder systems (CRS) show promise for increasing preventive services such as colorectal cancer (CRC) screening. However, prior research has not evaluated a generalizable CRS across diverse, community primary care practices. We evaluated whether a generalizable CRS, ClinfoTracker, could improve screening rates for CRC in diverse primary care practices. Methods The study was a prospective trial to evaluate ClinfoTracker using historical control data in 12 Great Lakes Research In Practice Network community-based, primary care practices distributed from Southeast to Upper Peninsula Michigan. Our outcome measures were pre- and post-study practice-level CRC screening rates among patients seen during the 9-month study period. Ability to maintain the CRS was measured by days of reminder printing. Field notes were used to examine each practice’s cohesion and technology capabilities. Results All but one practice increased their CRC screening rates, ranging from 3.3% to 16.8% improvement. t tests adjusted for within practice correlation showed improvement in screening rates across all 12 practices, from 41.7% to 50.9%, P = 0.002. Technology capabilities impacted printing days (74% for high technology vs. 45% for low technology practices, P = 0.01), and cohesion demonstrated an impact trend for screening (15.3% rate change for high cohesion vs. 7.9% for low cohesion practices). Conclusions Implementing a generalizable CRS in diverse primary care practices yielded significant improvements in CRC screening rates. Technology capabilities are important in maintaining the system, but practice cohesion may have a greater influence on screening rates. This work has important implications for practices implementing reminder systems. PMID:18725836

Hepatitis A and B screening and vaccination rates among patients with chronic liver disease.

PubMed

Ramirez, Jonathan C; Ackerman, Kimberly; Strain, Sasha C; Ahmed, Syed T; de Los Santos, Mario J; Sears, Dawn

2016-01-01

Vaccinations against hepatitis A virus (HAV) and hepatitis B virus (HBV) are recommended for patients with chronic liver disease (CLD), yet implementation of these recommendations is lacking. This study reviewed HAV and HBV antibody testing and vaccination status of patients with CLD. In 2008, we began using pre-printed liver order sets, which included vaccination options. We compared Scott & White liver clinic CLD patient records from 2005 (238) with patient records from 2008 (792). Screening rates for immunity and vaccination rates of those lacking immunity were calculated. In 2005, 66% of CLD patients were screened for HAV immunity. In 2008, 56% of CLD patients were screened. The HAV vaccination completion rate was 37% in 2005, while in 2008, the rate was 46%. In 2005, 66% of CLD patients were screened for HBV immunity; in 2008, 56 % CLD patients were screened. The HBV vaccination completion rate was 26% in 2005 compared with 36% in 2008. Although there was a lower percentage of screening in 2008, the overall number of patients tripled between 2005 and 2008. There was a significant increase in the total number of patients screened and vaccinated in 2008. Some physicians may have vaccinated their patients without checking for immunity. In January 2008, we implemented pre-printed order sets with checkboxes to help remind providers to order labs to screen for immunity against HAV and HBV and to order vaccinations for those who lacked immunity. The use of these sets may have aided in the increase of vaccination completion rates.

3D-printing techniques in a medical setting: a systematic literature review.

PubMed

Tack, Philip; Victor, Jan; Gemmel, Paul; Annemans, Lieven

2016-10-21

Three-dimensional (3D) printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. This paper summarizes the literature on surgical 3D-printing applications used on patients, with a focus on reported clinical and economic outcomes. Three major literature databases were screened for case series (more than three cases described in the same study) and trials of surgical applications of 3D printing in humans. 227 surgical papers were analyzed and summarized using an evidence table. The papers described the use of 3D printing for surgical guides, anatomical models, and custom implants. 3D printing is used in multiple surgical domains, such as orthopedics, maxillofacial surgery, cranial surgery, and spinal surgery. In general, the advantages of 3D-printed parts are said to include reduced surgical time, improved medical outcome, and decreased radiation exposure. The costs of printing and additional scans generally increase the overall cost of the procedure. 3D printing is well integrated in surgical practice and research. Applications vary from anatomical models mainly intended for surgical planning to surgical guides and implants. Our research suggests that there are several advantages to 3D-printed applications, but that further research is needed to determine whether the increased intervention costs can be balanced with the observable advantages of this new technology. There is a need for a formal cost-effectiveness analysis.

Factors Affecting the Reading Media Used by Visually Impaired Adults

ERIC Educational Resources Information Center

Goudiras, Dimitrios B.; Papadopoulos, Konstantinos S.; Koutsoklenis, Athanasios Ch.; Papageorgiou, Virginia E.; Stergiou, Maria S.

2009-01-01

The aim of this study was to examine reading media (braille, cassettes, screen-reader, screen-magnifier, large print, low vision aids, CCTV) used by visually impaired adults. This article reports the results of a research project involving 100 people with visual impairment. The participants were interviewed and asked to fill in a questionnaire to…

Videotex: Words on the TV Screen. Viewdata, Teletext and the Rest.

ERIC Educational Resources Information Center

Howkins, John, Ed.

1979-01-01

This theme issue focuses on the development of telephone-based videotex systems that use television sets and the telephone with the addition of a simple keyboard to access banks of information available on computers and to receive information in print on the television screen. A series of articles are included on Prestel, a telephone-based…

Screening for Behavioral Health Issues in Children Enrolled in Massachusetts Medicaid

PubMed Central

Penfold, Robert; Arsenault, Lisa; Zhang, Fang; Murphy, Michael; Wissow, Larry

2014-01-01

OBJECTIVES: To understand mandated behavioral health (BH) screening in Massachusetts Medicaid including characteristics of screened children, predictors of positive screens, and whether screening identifies children without a previous BH history. METHODS: Massachusetts mandated BH screening in particularly among underidentified groups. 2008. Providers used a billing code and modifier to indicate a completed screen and whether a BH need was identified. Using MassHealth claims data, children with ≥300 days of eligibility in fiscal year (FY) 2009 were identified and categorized into groups based on first use of the modifier, screening code, or claim. Bivariate analyses were conducted to determine differences among groups. BH history was examined by limiting the sample to those continuously enrolled in FY 2008 and 2009. Multivariate logistic regression was used to determine predictors of positive screens. RESULTS: Of 355 490 eligible children, 46% had evidence of screening. Of those with modifiers, 12% were positive. Among continuously enrolled children (FY 2008 and FY 2009) with evidence of screening, 43% with positive modifiers had no BH history. This “newly identified” group were more likely to be female, younger, minority, and from rural residences (P < .0001). Among children with modifiers; gender (male), age (5–7), being in foster care, recent BH history, and Hispanic ethnicity predicted having a positive modifier. CONCLUSIONS: The high rate of newly identified Medicaid children with a BH need suggests that screening is performing well, particularly among underidentified groups. To better assess screening value, future work on cost-effectiveness and the impact on subsequent mental health treatment is needed. PMID:24298005

Printable Electrochemical Biosensors: A Focus on Screen-Printed Electrodes and Their Application

PubMed Central

Yamanaka, Keiichiro; Vestergaard, Mun’delanji C.; Tamiya, Eiichi

2016-01-01

In this review we present electrochemical biosensor developments, focusing on screen-printed electrodes (SPEs) and their applications. In particular, we discuss how SPEs enable simple integration, and the portability needed for on-field applications. First, we briefly discuss the general concept of biosensors and quickly move on to electrochemical biosensors. Drawing from research undertaken in this area, we cover the development of electrochemical DNA biosensors in great detail. Through specific examples, we describe the fabrication and surface modification of printed electrodes for sensitive and selective detection of targeted DNA sequences, as well as integration with reverse transcription-polymerase chain reaction (RT-PCR). For a more rounded approach, we also touch on electrochemical immunosensors and enzyme-based biosensors. Last, we present some electrochemical devices specifically developed for use with SPEs, including USB-powered compact mini potentiostat. The coupling demonstrates the practical use of printable electrode technologies for application at point-of-use. Although tremendous advances have indeed been made in this area, a few challenges remain. One of the main challenges is application of these technologies for on-field analysis, which involves complicated sample matrices. PMID:27775661

Roll-to-Roll Screen Printed Radio Frequency Identification Transponder Antennas for Vehicle Tracking Systems

NASA Astrophysics Data System (ADS)

Zichner, Ralf; Baumann, Reinhard R.

2013-05-01

Vehicle tracking systems based on ultra high frequency (UHF) radio frequency identification (RFID) technology are already introduced to control the access to car parks and corporate premises. For this field of application so-called Windshield RFID transponder labels are used, which are applied to the inside of the windshield. State of the art for manufacturing these transponder antennas is the traditional lithography/etching approach. Furthermore the performance of these transponders is limited to a reading distance of approximately 5 m which results in car speed limit of 5 km/h for identification. However, to achieve improved performance compared to existing all-purpose transponders and a dramatic cost reduction, an optimized antenna design is needed which takes into account the special dielectric and in particular metallic car environment of the tag and an roll-to-roll (R2R) printing manufacturing process. In this paper we focus on the development of a customized UHF RFID transponder antenna design, which is adopted for vehicle geometry as well as R2R screen printing manufacturing processes.

Effect of Ultrasonic Vibration on Mechanical Properties of 3D Printing Non-Crystalline and Semi-Crystalline Polymers.

PubMed

Li, Guiwei; Zhao, Ji; Wu, Wenzheng; Jiang, Jili; Wang, Bofan; Jiang, Hao; Fuh, Jerry Ying Hsi

2018-05-17

Fused deposition modeling 3D printing has become the most widely used additive manufacturing technology because of its low manufacturing cost and simple manufacturing process. However, the mechanical properties of the 3D printing parts are not satisfactory. Certain pressure and ultrasonic vibration were applied to 3D printed samples to study the effect on the mechanical properties of 3D printed non-crystalline and semi-crystalline polymers. The tensile strength of the semi-crystalline polymer polylactic acid was increased by 22.83% and the bending strength was increased by 49.05%, which were almost twice the percentage increase in the tensile strength and five times the percentage increase in the bending strength of the non-crystalline polymer acrylonitrile butadiene styrene with ultrasonic strengthening. The dynamic mechanical properties of the non-crystalline and semi-crystalline polymers were both improved after ultrasonic enhancement. Employing ultrasonic energy can significantly improve the mechanical properties of samples without modifying the 3D printed material or adjusting the forming process parameters.

A screen-printed Ce 0.8Sm 0.2O 1.9 film solid oxide fuel cell with a Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ cathode

NASA Astrophysics Data System (ADS)

Zhang, Yaohui; Huang, Xiqiang; Lu, Zhe; Liu, Zhiguo; Ge, Xiaodong; Xu, Jiahuan; Xin, Xianshuang; Sha, Xueqing; Su, Wenhui

Screen-printing technology was developed to fabricate Ce 0.8Sm 0.2O 1.9 (SDC) electrolyte films onto porous NiO-SDC green anode substrates. After sintering at 1400 °C for 4 h, a gas-tight SDC film with a thickness of 12 μm was obtained. A novel cathode material of Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ was subsequently applied onto the sintered SDC electrolyte film also by screen-printing and sintered at 970 °C for 3 h to get a single cell. A fuel cell of Ni-SDC/SDC (12 μm)/Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ provides the maximum power densities of 1280, 1080, 670, 370, 180 and 73 mW cm -2 at 650, 600, 555, 505, 455 and 405 °C, respectively, using hydrogen as fuel and stationary air as oxidant. When dry methane was used as fuel, the maximum power densities are 876, 568, 346 and 114 mW cm -2 at 650, 600, 555 and 505 °C, respectively. The present fuel cell shows excellent performance at lowered temperatures.

Facile synthesis of Prussian blue nanocubes/silver nanowires network as a water-based ink for the direct screen-printed flexible biosensor chips.

PubMed

Yang, Pengqi; Peng, Jingmeng; Chu, Zhenyu; Jiang, Danfeng; Jin, Wanqin

2017-06-15

The large-scale fabrication of nanocomposite based biosensors is always a challenge in the technology commercialization from laboratory to industry. In order to address this issue, we have designed a facile chemical method of fabricated nanocomposite ink applied to the screen-printed biosensor chip. This ink can be derived in the water through the in-situ growth of Prussian blue nanocubes (PBNCs) on the silver nanowires (AgNWs) to construct a composite nanostructure by a facile chemical method. Then a miniature flexible biosensor chip was screen-printed by using the prepared nanocomposite ink. Due to the synergic effects of the large specific surface area, high conductivity and electrocatalytic activity from AgNWs and PBNCs, the as-prepared biosensor chip exhibited a fast response (<3s)， a wider linear response from 0.01 to 1.3mM with an ultralow LOD=5µm, and the ultrahigh sensitivities of 131.31 and 481.20µAmM -1 cm -2 for the detections of glucose and hydrogen peroxide (H 2 O 2 ), respectively. Furthermore, the biosensor chip exhibited excellent stability, good reproducibility and high anti-interference ability towards physiological substances under a very low working potential of -0.05. Hence, the proposed biosensor chip also showed a promising potential for the application in practical analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

A WLED based on LuAG:Ce3+ PiG coated red-emitting K2SiF6:Mn4+ phosphor by screen-printing

NASA Astrophysics Data System (ADS)

Cao, Rui; Wu, Lingchao; Di, Xiaoxuan; Li, Pengzhi; Hu, Guangcai; Liang, Xiaojuan; Xiang, Weidong

2017-08-01

It is high-profile that the use of phosphor-in-glass (PiG) is extensive because of its excellent advantages in thermal resistance and lifetime aspects, and so on. Here, white light-emitting diodes (WLED) based on LuAG:Ce3+ PiG coated red-emitting K2SiF6:Mn4+ (KSF) phosphors by screen-printing are fabricated. Among all of these, the commercial LuAG phosphors and glass raw materials of TeO2-based glass, were weighted and milled in an agate thoroughly. Then, the mixture was melted and sintered at 850 K or so for 20 min in the ambient atmosphere through low temperature co-fired method, cold-forming LuAG PiG clump and cut into different LuAG PiG thicknesses. After that, the commercial red phosphor KSF was coated on LuAG PiG by screen-printing technique. Finally, high-performance WLEDs based on the TeO2-based glass were obtained, tested and characterized, which exhibit a highest color rendering index of 94.1, a lowest color temperature of 3744 K and a largest luminous efficiency of 101.02 lm·W-1. Most noticeably of all, the promising method has excellent developing potential for industrialization in high-power WLED.

Characterization of Screen-Printed Organic Electrochemical Transistors to Detect Cations of Different Sizes.

PubMed

Contat-Rodrigo, Laura; Pérez-Fuster, Clara; Lidón-Roger, José Vicente; Bonfiglio, Annalisa; García-Breijo, Eduardo

2016-09-28

A novel screen-printing fabrication method was used to prepare organic electrochemical transistors (OECTs) based on poly(3,4-ethylenedioxythiophene) doped with polysterene sulfonate (PEDOT:PSS). Initially, three types of these screen-printed OECTs with a different channel and gate areas ratio were compared in terms of output characteristics, transfer characteristics, and current modulation in a phosphate buffered saline (PBS) solution. Results confirm that transistors with a gate electrode larger than the channel exhibit higher modulation. OECTs with this geometry were therefore chosen to investigate their ion-sensitive properties in aqueous solutions of cations of different sizes (sodium and rhodamine B). The effect of the gate electrode was additionally studied by comparing these all-PEDOT:PSS transistors with OECTs with the same geometry but with a non-polarizable metal gate (Ag). The operation of the all-PEDOT:PSS OECTs yields a response that is not dependent on a Na⁺ or rhodamine concentration. The weak modulation of these transistors can be explained assuming that PEDOT:PSS behaves like a supercapacitor. In contrast, the operation of Ag-Gate OECTs yields a response that is dependent on ion concentration due to the redox reaction taking place at the gate electrode with Cl - counter-ions. This indicates that, for cation detection, the response is maximized in OECTs with non-polarizable gate electrodes.

A novel fabrication method of carbon electrodes using 3D printing and chemical modification process.

PubMed

Tian, Pan; Chen, Chaoyang; Hu, Jie; Qi, Jin; Wang, Qianghua; Chen, Jimmy Ching-Ming; Cavanaugh, John; Peng, Yinghong; Cheng, Mark Ming-Cheng

2017-11-23

Three-dimensional (3D) printing is an emerging technique in the field of biomedical engineering and electronics. This paper presents a novel biofabrication method of implantable carbon electrodes with several advantages including fast prototyping, patient-specific and miniaturization without expensive cleanroom. The method combines stereolithography in additive manufacturing and chemical modification processes to fabricate electrically conductive carbon electrodes. The stereolithography allows the structures to be 3D printed with very fine resolution and desired shapes. The resin is then chemically modified to carbon using pyrolysis to enhance electrochemical performance. The electrochemical characteristics of 3D printing carbon electrodes are assessed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacitance of 3D printing carbon electrodes is much higher than the same sized platinum (Pt) electrode. In-vivo electromyography (EMG) recording, 3D printing carbon electrodes exhibit much higher signal-to-noise ratio (40.63 ± 7.73) than Pt electrodes (14.26 ± 6.83). The proposed biofabrication method is envisioned to enable 3D printing in many emerging applications in biomedical engineering and electronics.

Smart options for simultaneous functionalization and pigment coloration of cellulosic/wool blends.

PubMed

Ibrahim, N A; Khalil, H M; El-Zairy, E M R; Abdalla, W A

2013-07-01

The present innovative research work deals with the individual use of chitosan (2.5 g/kg), Aloe vera (10 g/kg), triclosan (10 g/kg), TiO2-nanoparticles (TiO2-NP's, 10 g/kg), silicon micro-emulsion (20 g/kg) or a water/oil-repellent agent (40 g/kg) for modifying the pigment print paste to produce functionalized cotton/wool and viscose/wool pigment prints in one step process. The imparted functional properties such as antibacterial, antibacterial/UV-protection, soft-handle or water/oil-repellency together with the change in the printing properties were evaluated. Some of the obtained pigment prints were characterized by scanning electron microscope (SEM), and energy dispersive X-rays (EDX) to confirm deposition of certain functional additives on printed fabrics. The wide-range of imparted functional properties together with the depth of the obtained pigment prints were maintained over 80% even after 15 consecutive laundering cycles. The extent of retention in functional and pigment printing properties is influenced by the type of functional additive as well as the kind of substrate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Patterned surface with controllable wettability for inkjet printing of flexible printed electronics.

PubMed

Nguyen, Phuong Q M; Yeo, Lip-Pin; Lok, Boon-Keng; Lam, Yee-Cheong

2014-03-26

Appropriate control of substrate surface properties prior to inkjet printing could be employed to improve the printing quality of fine resolution structures. In this paper, novel methods to fabricate patterned surfaces with a combination of hydrophilic and hydrophobic properties are investigated. The results of inkjet printing of PEDOT/PSS conductive ink on these modified surfaces are presented. Selective wetting was achieved via a two-step hydrophilic-hydrophobic coating of 3-aminopropyl trimethoxysilane (APTMS) and 3M electronic grade chemical respectively on PET surfaces; this was followed by a selective hydrophilic treatment (either atmospheric O2/Ar plasma or UV/ozone surface treatment) with the aid of a Nickel stencil. Hydrophobic regions with water contact angle (WCA) of 105° and superhydrophilic regions with WCA <5° can be achieved on a single surface. During inkjet printing of the treated surfaces, PEDOT/PSS ink spread spontaneously along the hydrophilic areas while avoiding the hydrophobic regions. Fine features smaller than the inkjet droplet size (approximately 55 μm in diameter) can be successfully printed on the patterned surface with high wettability contrast.

Screening of lipid composition for scalable fabrication of solvent free lipid microarrays

NASA Astrophysics Data System (ADS)

Ghazanfari, Lida; Lenhert, Steven

2016-12-01

Liquid microdroplet arrays on surfaces are a promising approach to the miniaturization of laboratory processes such as high throughput screening. The fluid nature of these droplets poses unique challenges and opportunities in their fabrication and application, particularly for the scalable integration of multiple materials over large areas and immersion into cell culture solution. Here we use pin spotting and nanointaglio printing to screen a library of lipids and their mixtures for their compatibility with these fabrication processes, as well as stability upon immersion into aqueous solution. More than 200 combinations of natural and synthetic oils composed of fatty acids, triglycerides, and hydrocarbons were tested for their pin-spotting and nanointaglio print quality and their ability to contain the fluorescent compound TRITC upon immersion in water. A combination of castor oil and hexanoic acid at the ratio of 1:1 (w/w) was found optimal for producing reproducible patterns that are stable upon immersion into water. This method is capable of large scale nano-materials integration.

Flexible Piezoresistive Sensors Embedded in 3D Printed Tires

PubMed Central

Emon, Md Omar Faruk; Choi, Jae-Won

2017-01-01

In this article, we report the development of a flexible, 3D printable piezoresistive pressure sensor capable of measuring force and detecting the location of the force. The multilayer sensor comprises of an ionic liquid-based piezoresistive intermediate layer in between carbon nanotube (CNT)-based stretchable electrodes. A sensor containing an array of different sensing units was embedded on the inner liner surface of a 3D printed tire to provide with force information at different points of contact between the tire and road. Four scaled tires, as well as wheels, were 3D printed using a flexible and a rigid material, respectively, which were later assembled with a 3D-printed chassis. Only one tire was equipped with a sensor and the chassis was driven through a motorized linear stage at different speeds and load conditions to evaluate the sensor performance. The sensor was fabricated via molding and screen printing processes using a commercially available 3D-printable photopolymer as 3D printing is our target manufacturing technique to fabricate the entire tire assembly with the sensor. Results show that the proposed sensors, inserted in the 3D printed tire assembly, could detect forces, as well as their locations, properly. PMID:28327533

Flexible Piezoresistive Sensors Embedded in 3D Printed Tires.

PubMed

Emon, Md Omar Faruk; Choi, Jae-Won

2017-03-22

In this article, we report the development of a flexible, 3D printable piezoresistive pressure sensor capable of measuring force and detecting the location of the force. The multilayer sensor comprises of an ionic liquid-based piezoresistive intermediate layer in between carbon nanotube (CNT)-based stretchable electrodes. A sensor containing an array of different sensing units was embedded on the inner liner surface of a 3D printed tire to provide with force information at different points of contact between the tire and road. Four scaled tires, as well as wheels, were 3D printed using a flexible and a rigid material, respectively, which were later assembled with a 3D-printed chassis. Only one tire was equipped with a sensor and the chassis was driven through a motorized linear stage at different speeds and load conditions to evaluate the sensor performance. The sensor was fabricated via molding and screen printing processes using a commercially available 3D-printable photopolymer as 3D printing is our target manufacturing technique to fabricate the entire tire assembly with the sensor. Results show that the proposed sensors, inserted in the 3D printed tire assembly, could detect forces, as well as their locations, properly.

Three dimensional ink-jet printing of biomaterials using ionic liquids and co-solvents.

PubMed

Gunasekera, Deshani H A T; Kuek, SzeLee; Hasanaj, Denis; He, Yinfeng; Tuck, Christopher; Croft, Anna K; Wildman, Ricky D

2016-08-15

1-Ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) and 1-butyl-3-methylimidazolium acetate ([C4C1Im][OAc]) have been used as solvents for the dissolution and ink-jet printing of cellulose from 1.0 to 4.8 wt%, mixed with the co-solvents 1-butanol and DMSO. 1-Butanol and DMSO were used as rheological modifiers to ensure consistent printing, with DMSO in the range of 41-47 wt% producing samples within the printable range of a DIMATIX print-head used (printability parameter < 10) at 55 °C, whilst maintaining cellulose solubility. Regeneration of cellulose from printed samples using water was demonstrated, with the resulting structural changes to the cellulose sample assessed by scanning electron microscopy (SEM) and white light interferometry (WLI). These results indicate the potential of biorenewable materials to be used in the 3D additive manufacture process to generate single-component and composite materials.

3D Printing in the Laboratory: Maximize Time and Funds with Customized and Open-Source Labware.

PubMed

Coakley, Meghan; Hurt, Darrell E

2016-08-01

3D printing, also known as additive manufacturing, is the computer-guided process of fabricating physical objects by depositing successive layers of material. It has transformed manufacturing across virtually every industry, bringing about incredible advances in research and medicine. The rapidly growing consumer market now includes convenient and affordable "desktop" 3D printers. These are being used in the laboratory to create custom 3D-printed equipment, and a growing community of designers are contributing open-source, cost-effective innovations that can be used by both professionals and enthusiasts. User stories from investigators at the National Institutes of Health and the biomedical research community demonstrate the power of 3D printing to save valuable time and funding. While adoption of 3D printing has been slow in the biosciences to date, the potential is vast. The market predicts that within several years, 3D printers could be commonplace within the home; with so many practical uses for 3D printing, we anticipate that the technology will also play an increasingly important role in the laboratory. © 2016 Society for Laboratory Automation and Screening.

Screen-Printing Fabrication and Characterization of Stretchable Electronics

PubMed Central

Suikkola, Jari; Björninen, Toni; Mosallaei, Mahmoud; Kankkunen, Timo; Iso-Ketola, Pekka; Ukkonen, Leena; Vanhala, Jukka; Mäntysalo, Matti

2016-01-01

This article focuses on the fabrication and characterization of stretchable interconnects for wearable electronics applications. Interconnects were screen-printed with a stretchable silver-polymer composite ink on 50-μm thick thermoplastic polyurethane. The initial sheet resistances of the manufactured interconnects were an average of 36.2 mΩ/◽, and half the manufactured samples withstood single strains of up to 74%. The strain proportionality of resistance is discussed, and a regression model is introduced. Cycling strain increased resistance. However, the resistances here were almost fully reversible, and this recovery was time-dependent. Normalized resistances to 10%, 15%, and 20% cyclic strains stabilized at 1.3, 1.4, and 1.7. We also tested the validity of our model for radio-frequency applications through characterization of a stretchable radio-frequency identification tag. PMID:27173424

A Highly Thermostable In₂O₃/ITO Thin Film Thermocouple Prepared via Screen Printing for High Temperature Measurements.

PubMed

Liu, Yantao; Ren, Wei; Shi, Peng; Liu, Dan; Zhang, Yijun; Liu, Ming; Ye, Zuo-Guang; Jing, Weixuan; Tian, Bian; Jiang, Zhuangde

2018-03-23

An In₂O₃/ITO thin film thermocouple was prepared via screen printing. Glass additives were added to improve the sintering process and to increase the density of the In₂O₃/ITO films. The surface and cross-sectional images indicate that both the grain size and densification of the ITO and In₂O₃ films increased with the increase in annealing time. The thermoelectric voltage of the In₂O₃/ITO thermocouple was 53.5 mV at 1270 °C at the hot junction. The average Seebeck coefficient of the thermocouple was calculated as 44.5 μV/°C. The drift rate of the In₂O₃/ITO thermocouple was 5.44 °C/h at a measuring time of 10 h at 1270 °C.

Standing wave performance test of IDT-SAW transducer prepared by silk-screen printing

NASA Astrophysics Data System (ADS)

Wang, Ziping; Jiang, Zhengxuan; Chen, Liangbin; Li, Yefei; Li, Meixia; Wang, Shaohan

2018-05-01

With the advantages of high performance and low loss, interdigital surface acoustic wave (IDT-SAW) transducers are widely used in the fields of nondestructive testing, communication and broadcasting. The production, performance and application of surface acoustic wave (SAW) actuators has become a research hotspot. Based on the basic principle of SAW, an IDT-SAW transducer is designed and fabricated using silk-screen printing in this work. The experiment results show that in terms of SAW performance, the fabricated IDT-SAW transducer can generate standing wave fields comparable to those generated using traditional fabrication methods. The resonant frequency response of the IDT-SAW transducer and SAW attenuation coefficient were obtained by experiments. It has provided a method to test the transducer sensing performance by using fabricated IDT-SAW transducer.

Lead zirconate titanate-nickel zink ferrite thick-film composites: obtaining by the screen printing technique and magnetoelectric properties

NASA Astrophysics Data System (ADS)

Bush, A. A.; Shkuratov, V. Ya.; Chernykh, I. A.; Fetisov, Y. K.

2010-03-01

Layered thick-film composites containing one lead zirconate titanate (PZT) layer, one nickel zinc ferrite (NZF) layer, two PZT-NZF layers, or three PZT-NZF-PZT layers each 40-50 μm thick are prepared. The layers are applied by screen printing on a ceramic aluminum oxide substrate with a preformed contact (conducting) layer. The dielectric properties of the composites are studied in the temperature interval 80-900 K and the frequency interval 25 Hz-1 MHz. Polarized samples exhibit piezoelectric, pyroelectric, and magnetoelectric effects. In tangentially magnetized two- and three-layer composites, the magnetoelectric conversion factor equals 57 kV/(m T) at low frequencies and reaches 2000 kV/(m T) at the mechanical resonance frequency.

European Research and Development in Hybrid Flexible Electronics

DTIC Science & Technology

2010-07-01

printing lab houses industrial sized screen printers, dryers , roll-to-roll printers capable of flexographic and gravure printing on 10-inch-wide paper ... papers were to be identified within the Web of Science (WoS) by means of a “filter,” described below, and the analysis was intended to provide the...National Science Foundation. Public Papers of the Presidents 120:338. 2 NSF Investing in America’s Future: Strategic Plan FY 2006–2011. Washington, DC

Investigation of the adhesion properties of direct 3D printing of polymers and nanocomposites on textiles: Effect of FDM printing process parameters

NASA Astrophysics Data System (ADS)

Hashemi Sanatgar, Razieh; Campagne, Christine; Nierstrasz, Vincent

2017-05-01

In this paper, 3D printing as a novel printing process was considered for deposition of polymers on synthetic fabrics to introduce more flexible, resource-efficient and cost effective textile functionalization processes than conventional printing process like screen and inkjet printing. The aim is to develop an integrated or tailored production process for smart and functional textiles which avoid unnecessary use of water, energy, chemicals and minimize the waste to improve ecological footprint and productivity. Adhesion of polymer and nanocomposite layers which were 3D printed directly onto the textile fabrics using fused deposition modeling (FDM) technique was investigated. Different variables which may affect the adhesion properties including 3D printing process parameters, fabric type and filler type incorporated in polymer were considered. A rectangular shape according to the peeling standard was designed as 3D computer-aided design (CAD) to find out the effect of the different variables. The polymers were printed in different series of experimental design: nylon on polyamide 66 (PA66) fabrics, polylactic acid (PLA) on PA66 fabric, PLA on PLA fabric, and finally nanosize carbon black/PLA (CB/PLA) and multi-wall carbon nanotubes/PLA (CNT/PLA) nanocomposites on PLA fabrics. The adhesion forces were quantified using the innovative sample preparing method combining with the peeling standard method. Results showed that different variables of 3D printing process like extruder temperature, platform temperature and printing speed can have significant effect on adhesion force of polymers to fabrics while direct 3D printing. A model was proposed specifically for deposition of a commercial 3D printer Nylon filament on PA66 fabrics. In the following, among the printed polymers, PLA and its composites had high adhesion force to PLA fabrics.

Fully Printed Ultraflexible Supercapacitor Supported by a Single-Textile Substrate.

PubMed

Zhang, Huihui; Qiao, Yan; Lu, Zhisong

2016-11-30

Textile-based supercapacitors have recently attracted much attention owing to their great potential as energy storage components in wearable electronics. However, fabrication of a high-performance, fully printed, and ultraflexible supercapacitor based on a single textile still remains a great challenge. Herein, a facile, low-cost, and textile-compatible method involving screen printing and transfer printing is developed to construct all-solid-state supercapacitors on a single silk fabric. The system exhibits a high specific capacitance of 19.23 mF cm -2 at a current density of 1 mA cm -2 and excellent cycling stability with capacitance retention of 84% after 2000 charging/discharging cycles. In addition, the device possesses superior mechanical stability with stable performance and structures after 100 times of bending and twisting. A butterfly-patterned supercapacitor was manufactured to demonstrate the compatibility of the printing approaches to textile aesthetics. This work may provide a facile and versatile approach for fabricating rationally designed ultraflexible textile-based power-storage elements for potential applications in smart textiles and stretchable/flexible electronics.

3D-Printing in Congenital Cardiology: From Flatland to Spaceland.

PubMed

Deferm, Sébastien; Meyns, Bart; Vlasselaers, Dirk; Budts, Werner

2016-01-01

Medical imaging has changed to a great extent over the past few decades. It has been revolutionized by three-dimensional (3D) imaging techniques. Despite much of modern medicine relying on 3D imaging, which can be obtained accurately, we keep on being limited by visualization of the 3D content on two-dimensional flat screens. 3D-printing of graspable models could become a feasible technique to overcome this gap. Therefore, we printed pre- and postoperative 3D-models of a complex congenital heart defect. With this example, we intend to illustrate that these models hold value in preoperative planning, postoperative evaluation of a complex procedure, communication with the patient, and education of trainees. At this moment, 3D printing only leaves a small footprint, but makes already a big impression in the domain of cardiology and cardiovascular surgery. Further studies including more patients and more validated applications are needed to streamline 3D printing in the clinical setting of daily practice.

The Effects of Using Touch-Screen Devices on Students' Molecular Visualization and Representational Competence Skills

ERIC Educational Resources Information Center

McCollum, Brett M.; Regier, Lisa; Leong, Jaque; Simpson, Sarah; Sterner, Shayne

2014-01-01

The impact of touch-screen technology on spatial cognitive skills as related to molecular geometries was assessed through 102 one-on-one interviews with undergraduate students. Participants were provided with either printed 2D ball-and-stick images of molecules or manipulable projections of 3D molecular structures on an iPad. Following a brief…

Immunosensor based on electrodeposition of gold-nanoparticles and ionic liquid composite for detection of Salmonella pullorum.

PubMed

Wang, Dan; Dou, Wenchao; Zhao, Guangying; Chen, Yan

2014-11-01

In order to increase the reproducibility and stability of electrochemical immunosensor, which is a key issue for its application and popularization, an accurate and stable immunosensor for rapid detection of Salmonella pullorum (S. pullorum) was proposed in this study. The immunosensor was fabricated by modifying Screen-printed Carbon Electrode (SPCE) with electrodeposited gold nanoparticles (AuNPs), HRP-labeled anti-S. pullorum and ionic liquids (ILs) (AuNP/HRP/IL). AuNPs are electrodeposited on the working electrode surface to increase the amount of antibodies that bind to the electrode and then modified with ILs to protect the antibodies from being inactivated in the test environment and maintain their biological activity and the stability of the detection electrode. The electrochemical characteristics of the stepwise modified electrodes and the detection of S. pullorum were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). As shown in the results of the experiments, AuNPs with unique electrochemical properties as well as biocompatibility characteristics have been proven to be able to strengthen the antibody combination effectively and to increase the electrochemical response signal. In addition, a crucial assessment regarding implementation of stability and reproducibility analysis of a range of immunosensors is provided. We found that application of AuNPs/ILs in the immune modified electrodes showed obvious improvement when compared with other groups. Given their high levels of reproducibility, stability, target specificity and sensitivity, AuNPs and ILs were considered to be excellent elements for electrode modification. Copyright © 2014 Elsevier B.V. All rights reserved.

Nanoscale Resolution 3D Printing with Pin-Modified Electrified Inkjets for Tailorable Nano/Macrohybrid Constructs for Tissue Engineering.

PubMed

Kim, Jeong In; Kim, Cheol Sang

2018-04-18

Cells respond to their microenvironment, which is of a size comparable to that of the cells. The macroscale features of three-dimensional (3D) printing struts typically result in whole cell contact guidance (CCG). In contrast, at the nanoscale, where features are of a size similar to that of receptors of cells, the response of cells is more complex. The cell-nanotopography interaction involves nanoscale adhesion localized structures, which include cell adhesion-related particles that change in response to the clustering of integrin. For this reason, it is necessary to develop a technique for manufacturing tailorable nano/macrohybrid constructs capable of freely controlling the cellular activity. In this study, a hierarchical 3D nano- to microscale hybrid structure was fabricated by combinational processing of 3D printing and electrified inkjet spinning via pin motions. This method overcomes the disadvantages of conventional 3D printing, providing a novel combinatory technique for the fabrication of 3D hybrid constructs with excellent cell proliferation. Through a pin-modified electrified inkjet spinning, we have successfully fabricated customizable nano-/microscale hybrid constructs in a fibrous or mesh form, which can control the cell fate. We have conducted this study of cell-topography interactions from the fabrication approach to accelerate the development of next-generation 3D scaffolds.

Microcontact printing of self-assembled monolayers to pattern the light-emission of polymeric light-emitting diodes

NASA Astrophysics Data System (ADS)

Brondijk, J. J.; Li, X.; Akkerman, H. B.; Blom, P. W. M.; de Boer, B.

2009-04-01

By patterning a self-assembled monolayer (SAM) of thiolated molecules with opposing dipole moments on a gold anode of a polymer light-emitting diode (PLED), the charge injection and, therefore, the light-emission of the device can be controlled with a micrometer-scale resolution. Gold surfaces were modified with SAMs based on alkanethiols and perfluorinated alkanethiols, applied by microcontact printing, and their work functions have been measured. The molecules form a chemisorbed monolayer of only ˜1.5 nm on the gold surface, thereby locally changing the work function of the metal. Kelvin probe measurements show that the local work function can be tuned from 4.3 to 5.5 eV, which implies that this anode can be used as a hole blocking electrode or as a hole injecting electrode, respectively, in PLEDs based on poly( p-phenylene vinylene) (PPV) derivatives. By microcontact printing of SAMs with opposing dipole moments, the work function was locally modified and the charge injection in the PLED could be controlled down to the micrometer length scale. Consequently, the local light-emission exhibits a high contrast. Microcontact printing of SAMs is a simple and inexpensive method to pattern, with micrometer resolution, the light-emission for low-end applications like static displays.

Effect of temperature, viscosity and surface tension on gelatine structures produced by modified 3D printer

NASA Astrophysics Data System (ADS)

Kalkandelen, C.; Ozbek, B.; Ergul, N. M.; Akyol, S.; Moukbil, Y.; Oktar, F. N.; Ekren, N.; Kılıc, O.; Kılıc, B.; Gunduz, O.

2017-12-01

In the present study, gelatine scaffolds were manufactured by using modified 3D (3 Dimensional) printing machine and the effect of different parameters on scaffold structure were investigated. Such as; temperature, viscosity and surface tension of the gelatine solutions. The varying of gelatine solutions (1, 3, 5, 10, 15 and 20 wt.%) were prepared and characterized. It has been detected that, viscosity of those solutions were highly influenced by temperature and gelatine concentration. Specific CAD (Computer Assistant Design) model which has 67% porosity and original design were created via computer software. However, at high temperatures gelatine solutions caused like liquid but at the lower temperatures were observed the opposite behaviour. In addition to that, viscosity of 1,3,5 wt.% solutions were not enough to build a structure and 20 wt.% gelatine solution too hard to handle, because of the sudden viscosity changes with temperature. Even though, scaffold of the 20 wt.% gelatine solution printed hardly but it was observed the best printed solutions, which were 10 and 15 wt.% gelatine solutions. As a result, 3D printing of gelatine were found the values of the best temperature, viscosity, surface tension and gelatine concentration such as 25-35 °C, 36-163 cP, 46-59 mN/m and 15 wt.% gelatine concentration respectively.

3D-printed phase waveplates for THz beam shaping

NASA Astrophysics Data System (ADS)

Gospodaric, J.; Kuzmenko, A.; Pimenov, Anna; Huber, C.; Suess, D.; Rotter, S.; Pimenov, A.

2018-05-01

The advancement of 3D-printing opens up a new way of constructing affordable custom terahertz (THz) components due to suitable printing resolution and THz transparency of polymer materials. We present a way of calculating, designing, and fabricating a THz waveplate that phase-modulates an incident THz beam (λ0 = 2.14 mm) in order to create a predefined intensity profile of the optical wavefront on a distant image plane. Our calculations were performed for two distinct target intensities with the use of a modified Gerchberg-Saxton algorithm. The resulting phase-modulating profiles were used to model the polylactide elements, which were printed out with a commercially available 3D-printer. The results were tested in a THz experimental setup equipped with a scanning option, and they showed good agreement with theoretical predictions.

Poly(dimethylsiloxane) cross-linked carbon paste electrodes for microfluidic electrochemical sensing.

PubMed

Sameenoi, Yupaporn; Mensack, Meghan M; Boonsong, Kanokporn; Ewing, Rebecca; Dungchai, Wijitar; Chailapakul, Orawan; Cropek, Donald M; Henry, Charles S

2011-08-07

Recently, the development of electrochemical biosensors as part of microfluidic devices has garnered a great deal of attention because of the small instrument size and portability afforded by the integration of electrochemistry in microfluidic systems. Electrode fabrication, however, has proven to be a major obstacle in the field. Here, an alternative method to create integrated, low cost, robust, patternable carbon paste electrodes (CPEs) for microfluidic devices is presented. The new CPEs are composed of graphite powder and a binder consisting of a mixture of poly(dimethylsiloxane) (PDMS) and mineral oil. The electrodes are made by filling channels molded in previously cross-linked PDMS using a method analogous to screen printing. The optimal binder composition was investigated to obtain electrodes that were physically robust and performed well electrochemically. After studying the basic electrochemistry, the PDMS-oil CPEs were modified with multi-walled carbon nanotubes (MWCNT) and cobalt phthalocyanine (CoPC) for the detection of catecholamines and thiols, respectively, to demonstrate the ease of electrode chemical modification. Significant improvement of analyte signal detection was observed from both types of modified CPEs. A nearly 2-fold improvement in the electrochemical signal for 100 μM dithiothreitol (DTT) was observed when using a CoPC modified electrode (4.0 ± 0.2 nA (n = 3) versus 2.5 ± 0.2 nA (n = 3)). The improvement in signal was even more pronounced when looking at catecholamines, namely dopamine, using MWCNT modified CPEs. In this case, an order of magnitude improvement in limit of detection was observed for dopamine when using the MWCNT modified CPEs (50 nM versus 500 nM). CoPC modified CPEs were successfully used to detect thiols in red blood cell lysate while MWCNT modified CPEs were used to monitor temporal changes in catecholamine release from PC12 cells following stimulation with potassium.

21 CFR 176.130 - Anti-offset substances.

Code of Federal Regulations, 2013 CFR

2013-04-01

... in printing and decorating paper and paperboard used for food packaging in accordance with the...: Substances Limitations Carbon tetrachloride Methyl hydrogen polysiloxanes Industrial starch—modified...

21 CFR 176.130 - Anti-offset substances.

Code of Federal Regulations, 2012 CFR

2012-04-01

... in printing and decorating paper and paperboard used for food packaging in accordance with the...: Substances Limitations Carbon tetrachloride Methyl hydrogen polysiloxanes Industrial starch—modified...

21 CFR 176.130 - Anti-offset substances.

Code of Federal Regulations, 2010 CFR

2010-04-01

... in printing and decorating paper and paperboard used for food packaging in accordance with the...: Substances Limitations Carbon tetrachloride Methyl hydrogen polysiloxanes Industrial starch—modified...

21 CFR 176.130 - Anti-offset substances.

Code of Federal Regulations, 2011 CFR

2011-04-01

... in printing and decorating paper and paperboard used for food packaging in accordance with the...: Substances Limitations Carbon tetrachloride Methyl hydrogen polysiloxanes Industrial starch—modified...

76 FR 68690 - Rules and Regulations Under the Textile Fiber Products Identification Act

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-07

..., particularly small businesses? (19) Should the Commission modify the Rules to add or clarify definitions of... Products Identification Act; add or clarify definitions of terms set forth in the Rules; and modify its consumer and business education materials and continue printing paper copies of these materials. In...

Thick-film materials for silicon photovoltaic cell manufacture

NASA Technical Reports Server (NTRS)

Field, M. B.

1977-01-01

Thick film technology is applicable to three areas of silicon solar cell fabrication; metallization, junction formation, and coating for protection of screened ohmic contacts, particularly wrap around contacts, interconnection and environmental protection. Both material and process parameters were investigated. Printed ohmic contacts on n- and p-type silicon are very sensitive to the processing parameters of firing time, temperature, and atmosphere. Wrap around contacts are easily achieved by first printing and firing a dielectric over the edge and subsequently applying a low firing temperature conductor. Interconnection of cells into arrays can be achieved by printing and cofiring thick film metal pastes, soldering, or with heat curing conductive epoxies on low cost substrates. Printed (thick) film vitreous protection coatings do not yet offer sufficient optical uniformity and transparency for use on silicon. A sprayed, heat curable SiO2 based resin shows promise of providing both optical matching and environmental protection.

Determination of the resistance of fabric printed with triclosan microcapsules to the action of soil micro-flora

NASA Astrophysics Data System (ADS)

Golja, B.; Forte Tavčer, P.

2017-10-01

Microcapsules with a pressure-sensitive melamine-formaldehyde wall and triclosan core were printed to 100% cotton fabric with screen printing technique. Previous research showed excellent antibacterial activity (estimated for E. Coli and S. Aureus) of such fabric, so our aim in this research was to determine its resistance to the action of microorganisms present in the soil. The soil burial test was conducted. The breaking strength of the buried samples was measured and also the scanning electron microscope analysis was done. The results showed that none of the samples are resistant to decay. It is evident from SEM micrographs that on all of the buried samples greater morphological changes occur due to the functions of the soil microflora. It can be concluded that the samples printed with triclosan microcapsules are biodegradable which is environmentally preferable.

Fabrication of individual alginate-TCP scaffolds for bone tissue engineering by means of powder printing.

PubMed

Castilho, Miguel; Rodrigues, Jorge; Pires, Inês; Gouveia, Barbara; Pereira, Manuel; Moseke, Claus; Groll, Jürgen; Ewald, Andrea; Vorndran, Elke

2015-01-06

The development of polymer-calcium phosphate composite scaffolds with tailored architectures and properties has great potential for bone regeneration. Herein, we aimed to improve the functional performance of brittle ceramic scaffolds by developing a promising biopolymer-ceramic network. For this purpose, two strategies, namely, direct printing of a powder composition consisting of a 60:40 mixture of α/β-tricalcium phosphate (TCP) powder and alginate powder or vacuum infiltration of printed TCP scaffolds with an alginate solution, were tracked. Results of structural characterization revealed that the scaffolds printed with 2.5 wt% alginate-modified TCP powders presented a uniformly distributed and interfusing alginate TCP network. Mechanical results indicated a significant increase in strength, energy to failure and reliability of powder-modified scaffolds with an alginate content in the educts of 2.5 wt% when compared to pure TCP, as well as to TCP scaffolds containing 5 wt% or 7.5 wt% in the educts, in both dry and wet states. Culture of human osteoblast cells on these scaffolds also demonstrated a great improvement of cell proliferation and cell viability. While in the case of powder-mixed alginate TCP scaffolds, isolated alginate gels were formed between the calcium phosphate crystals, the vacuum-infiltration strategy resulted in the covering of the surface and internal pores of the TCP scaffold with a thin alginate film. Furthermore, the prediction of the scaffolds' critical fracture conditions under more complex stress states by the applied Mohr fracture criterion confirmed the potential of the powder-modified scaffolds with 2.5 wt% alginate in the educts as structural biomaterial for bone tissue engineering.

4D printing of a self-morphing polymer driven by a swellable guest medium.

PubMed

Su, Jheng-Wun; Tao, Xiang; Deng, Heng; Zhang, Cheng; Jiang, Shan; Lin, Yuyi; Lin, Jian

2018-01-31

There is a significant need of advanced materials that can be fabricated into functional devices with defined three-dimensional (3D) structures for application in tissue engineering, flexible electronics, and soft robotics. This need motivates an emerging four-dimensional (4D) printing technology, by which printed 3D structures consisting of active materials can transform their configurations over time in response to stimuli. Despite the ubiquity of active materials in performing self-morphing processes, their potential for 4D printing has not been fully explored to date. In this study, we demonstrate 4D printing of a commercial polymer, SU-8, which has not been reported to date in this field. The working principle is based on a self-morphing process of the printed SU-8 structures through spatial control of the swelling medium inside the polymer matrix by a modified process. To understand the self-morphing behavior, fundamental studies on the effect of the geometries including contours and filling patterns were carried out. A soft electronic device as an actuator was demonstrated to realize an application of this programmable polymer using the 3D printing technology. These studies provide a new paradigm for application of SU-8 in 4D printing, paving a new route to the exploration of more potential candidates by this demonstrated strategy.

Temperature-controlled microintaglio printing for high-resolution micropatterning of RNA molecules.

PubMed

Kobayashi, Ryo; Biyani, Manish; Ueno, Shingo; Kumal, Subhashini Raj; Kuramochi, Hiromi; Ichiki, Takanori

2015-05-15

We have developed an advanced microintaglio printing method for fabricating fine and high-density micropatterns and applied it to the microarraying of RNA molecules. The microintaglio printing of RNA reported here is based on the hybridization of RNA with immobilized complementary DNA probes. The hybridization was controlled by switching the RNA conformation via the temperature, and an RNA microarray with a diameter of 1.5 µm and a density of 40,000 spots/mm(2) with high contrast was successfully fabricated. Specifically, no size effects were observed in the uniformity of patterned signals over a range of microarray feature sizes spanning one order of magnitude. Additionally, we have developed a microintaglio printing method for transcribed RNA microarrays on demand using DNA-immobilized magnetic beads. The beads were arrayed on wells fabricated on a printing mold and the wells were filled with in vitro transcription reagent and sealed with a DNA-immobilized glass substrate. Subsequently, RNA was in situ synthesized using the bead-immobilized DNA as a template and printed onto the substrate via hybridization. Since the microintaglio printing of RNA using DNA-immobilized beads enables the fabrication of a microarray of spots composed of multiple RNA sequences, it will be possible to screen or analyze RNA functions using an RNA microarray fabricated by temperature-controlled microintaglio printing (TC-µIP). Copyright © 2014 Elsevier B.V. All rights reserved.

Going to the Audiologist

MedlinePlus

... Staying Safe Videos for Educators Search English Español Going to the Audiologist KidsHealth / For Kids / Going to ... of lines on the equipment screen or on piece of paper that prints out. Ask the audiologist ...

Screening for Specific Phobias

MedlinePlus

... Print this form Follow Us Facebook Twitter RSS YouTube Advertisement Find A Therapist Search our directory of ADAA mental health professional members who specialize in anxiety, depression and co-occurring disorders. Understand the Facts Anxiety ...

Method for formation of high quality back contact with screen-printed local back surface field

DOEpatents

Rohatgi, Ajeet; Meemongkolkiat, Vichai

2010-11-30

A thin silicon solar cell having a back dielectric passivation and rear contact with local back surface field is described. Specifically, the solar cell may be fabricated from a crystalline silicon wafer having a thickness from 50 to 500 micrometers. A barrier layer and a dielectric layer are applied at least to the back surface of the silicon wafer to protect the silicon wafer from deformation when the rear contact is formed. At least one opening is made to the dielectric layer. An aluminum contact that provides a back surface field is formed in the opening and on the dielectric layer. The aluminum contact may be applied by screen printing an aluminum paste having from one to 12 atomic percent silicon and then applying a heat treatment at 750 degrees Celsius.

Marked Object Recognition Multitouch Screen Printed Touchpad for Interactive Applications.

PubMed

Nunes, Jivago Serrado; Castro, Nelson; Gonçalves, Sergio; Pereira, Nélson; Correia, Vitor; Lanceros-Mendez, Senentxu

2017-12-01

The market for interactive platforms is rapidly growing, and touchscreens have been incorporated in an increasing number of devices. Thus, the area of smart objects and devices is strongly increasing by adding interactive touch and multimedia content, leading to new uses and capabilities. In this work, a flexible screen printed sensor matrix is fabricated based on silver ink in a polyethylene terephthalate (PET) substrate. Diamond shaped capacitive electrodes coupled with conventional capacitive reading electronics enables fabrication of a highly functional capacitive touchpad, and also allows for the identification of marked objects. For the latter, the capacitive signatures are identified by intersecting points and distances between them. Thus, this work demonstrates the applicability of a low cost method using royalty-free geometries and technologies for the development of flexible multitouch touchpads for the implementation of interactive and object recognition applications.

Application of Vacancy Injection Gettering to Improve Efficiency of Solar Cells Produced by Millinet Solar: Cooperative Research and Development Final Report, CRADA Number CRD-10-417

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sopori, B.

2012-07-01

NREL will apply vacancy injection gettering (VIG) to Millinet solar cells and evaluate the performance improvement produced by this process step. The VIG will be done in conjunction with the formation of a back, Al-alloyed, contact. Millinet Solar will provide NREL with cells having AR coating on the front side and screen-printed Al on the backside, which will be processed in the NREL's optical furnace to perform simultaneous VIG and back contact alloying with deep BSF. These cells will be sent back to Millinet solar for a screen-printed front/side contact mask, followed by a second firing at NREL. Detailed analysesmore » will be performed to determine improvements due to BSF and VIG.« less

Liquid-phase-deposited siloxane-based capping layers for silicon solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veith-Wolf, Boris; Wang, Jianhui; Hannu-Kuure, Milja

2015-02-02

We apply non-vacuum processing to deposit dielectric capping layers on top of ultrathin atomic-layer-deposited aluminum oxide (AlO{sub x}) films, used for the rear surface passivation of high-efficiency crystalline silicon solar cells. We examine various siloxane-based liquid-phase-deposited (LPD) materials. Our optimized AlO{sub x}/LPD stacks show an excellent thermal and chemical stability against aluminum metal paste, as demonstrated by measured surface recombination velocities below 10 cm/s on 1.3 Ωcm p-type silicon wafers after firing in a belt-line furnace with screen-printed aluminum paste on top. Implementation of the optimized LPD layers into an industrial-type screen-printing solar cell process results in energy conversion efficiencies ofmore » up to 19.8% on p-type Czochralski silicon.« less

Marked Object Recognition Multitouch Screen Printed Touchpad for Interactive Applications

PubMed Central

Nunes, Jivago Serrado; Castro, Nelson; Pereira, Nélson; Correia, Vitor; Lanceros-Mendez, Senentxu

2017-01-01

The market for interactive platforms is rapidly growing, and touchscreens have been incorporated in an increasing number of devices. Thus, the area of smart objects and devices is strongly increasing by adding interactive touch and multimedia content, leading to new uses and capabilities. In this work, a flexible screen printed sensor matrix is fabricated based on silver ink in a polyethylene terephthalate (PET) substrate. Diamond shaped capacitive electrodes coupled with conventional capacitive reading electronics enables fabrication of a highly functional capacitive touchpad, and also allows for the identification of marked objects. For the latter, the capacitive signatures are identified by intersecting points and distances between them. Thus, this work demonstrates the applicability of a low cost method using royalty-free geometries and technologies for the development of flexible multitouch touchpads for the implementation of interactive and object recognition applications. PMID:29194414

Catalytic Activity and Impedance Behavior of Screen-Printed Nickel Oxide as Efficient Water Oxidation Catalysts.

PubMed

Singh, Archana; Fekete, Monika; Gengenbach, Thomas; Simonov, Alexandr N; Hocking, Rosalie K; Chang, Shery L Y; Rothmann, Mathias; Powar, Satvasheel; Fu, Dongchuan; Hu, Zheng; Wu, Qiang; Cheng, Yi-Bing; Bach, Udo; Spiccia, Leone

2015-12-21

We report that films screen printed from nickel oxide (NiO) nanoparticles and microballs are efficient electrocatalysts for water oxidation under near-neutral and alkaline conditions. Investigations of the composition and structure of the screen-printed films by X-ray diffraction, X-ray absorption spectroscopy, and scanning electron microscopy confirmed that the material was present as the cubic NiO phase. Comparison of the catalytic activity of the microball films to that of films fabricated by using NiO nanoparticles, under similar experimental conditions, revealed that the microball films outperform nanoparticle films of similar thickness owing to a more porous structure and higher surface area. A thinner, less-resistive NiO nanoparticle film, however, was found to have higher activity per Ni atom. Anodization in borate buffer significantly improved the activity of all three films. X-ray photoelectron spectroscopy showed that during anodization, a mixed nickel oxyhydroxide phase formed on the surface of all films, which could account for the improved activity. Impedance spectroscopy revealed that surface traps contribute significantly to the resistance of the NiO films. On anodization, the trap state resistance of all films was reduced, which led to significant improvements in activity. In 1.00 m NaOH, both the microball and nanoparticle films exhibit high long-term stability and produce a stable current density of approximately 30 mA cm(-2) at 600 mV overpotential. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparative analysis of print and multimedia health materials: a review of the literature.

PubMed

Wilson, Elizabeth A H; Makoul, Gregory; Bojarski, Elizabeth A; Bailey, Stacy Cooper; Waite, Katherine R; Rapp, David N; Baker, David W; Wolf, Michael S

2012-10-01

Evaluate the evidence regarding the relative effectiveness of multimedia and print as modes of dissemination for patient education materials; examine whether development of these materials addressed health literacy. A structured literature review utilizing Medline, PsycInfo, and the Cumulative Index to the Nursing and Allied Health Literature (CINAHL), supplemented by reference mining. Of 738 studies screened, 30 effectively compared multimedia and print materials. Studies offered 56 opportunities for assessing the effect of medium on various outcomes (e.g., knowledge). In 30 instances (54%), no difference was noted between multimedia and print in terms of patient outcomes. Multimedia led to better outcomes vs. print in 21 (38%) comparisons vs. 5 (9%) instances for print. Regarding material development, 12 studies (40%) assessed readability and 5 (17%) involved patients in tool development. Multimedia appears to be a promising medium for patient education; however, the majority of studies found that print and multimedia performed equally well in practice. Few studies involved patients in material development, and less than half assessed the readability of materials. Future research should focus on comparing message-equivalent tools and assessing their effect on behavioral outcomes. Material development should include explicit attention to readability and patient input. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Towards roll-to-roll fabrication of electronics, optics, and optoelectronics for smart and intelligent packaging

NASA Astrophysics Data System (ADS)

Kololuoma, Terho K.; Tuomikoski, Markus; Makela, Tapio; Heilmann, Jali; Haring, Tomi; Kallioinen, Jani; Hagberg, Juha; Kettunen, Ilkka; Kopola, Harri K.

2004-06-01

Embedding of optoelectrical, optical, and electrical functionalities into low-cost products like packages and printed matter can be used to increase their information content. These functionalities make also possible the realization of new type of entertaining, impressive or guiding effects on the product packages and printed matter. For these purposes, components like displays, photodetectors, light sources, solar cells, battery elements, diffractive optical elements, lightguides, electrical conductors, resistors, transistors, switching elements etc. and their integration to functional modules are required. Additionally, the price of the components for low-end products has to be in cent scale or preferably below that. Therefore, new, cost-effective, and volume scale capable manufacturing techniques are required. Recent developments of liquid-phase processable electrical and optical polymeric, inorganic, and hybrid materials - inks - have made it possible to fabricate functional electrical, optical and optoelectrical components by conventional roll-to-roll techniques such as gravure printing, embossing, digital printing, offset, and screen printing on flexible paper and plastic like substrates. In this paper, we show our current achievements in the field of roll-to-roll fabricated, optics, electronics and optoelectronics. With few examples, we also demonstrate the printing and hot-embossing capabilities of table scale printing machines and VTT Electronic's 'PICO' roll-to-roll pilot production facility.

Effect of Ultrasonic Vibration on Mechanical Properties of 3D Printing Non-Crystalline and Semi-Crystalline Polymers

PubMed Central

Li, Guiwei; Zhao, Ji; Wu, Wenzheng; Jiang, Jili; Wang, Bofan; Jiang, Hao

2018-01-01

Fused deposition modeling 3D printing has become the most widely used additive manufacturing technology because of its low manufacturing cost and simple manufacturing process. However, the mechanical properties of the 3D printing parts are not satisfactory. Certain pressure and ultrasonic vibration were applied to 3D printed samples to study the effect on the mechanical properties of 3D printed non-crystalline and semi-crystalline polymers. The tensile strength of the semi-crystalline polymer polylactic acid was increased by 22.83% and the bending strength was increased by 49.05%, which were almost twice the percentage increase in the tensile strength and five times the percentage increase in the bending strength of the non-crystalline polymer acrylonitrile butadiene styrene with ultrasonic strengthening. The dynamic mechanical properties of the non-crystalline and semi-crystalline polymers were both improved after ultrasonic enhancement. Employing ultrasonic energy can significantly improve the mechanical properties of samples without modifying the 3D printed material or adjusting the forming process parameters. PMID:29772802

Three-dimensional (3D) printing of mouse primary hepatocytes to generate 3D hepatic structure.

PubMed

Kim, Yohan; Kang, Kyojin; Jeong, Jaemin; Paik, Seung Sam; Kim, Ji Sook; Park, Su A; Kim, Wan Doo; Park, Jisun; Choi, Dongho

2017-02-01

The major problem in producing artificial livers is that primary hepatocytes cannot be cultured for many days. Recently, 3-dimensional (3D) printing technology draws attention and this technology regarded as a useful tool for current cell biology. By using the 3D bio-printing, these problems can be resolved. To generate 3D bio-printed structures (25 mm × 25 mm), cells-alginate constructs were fabricated by 3D bio-printing system. Mouse primary hepatocytes were isolated from the livers of 6-8 weeks old mice by a 2-step collagenase method. Samples of 4 × 10 7 hepatocytes with 80%-90% viability were printed with 3% alginate solution, and cultured with well-defined culture medium for primary hepatocytes. To confirm functional ability of hepatocytes cultured on 3D alginate scaffold, we conducted quantitative real-time polymerase chain reaction and immunofluorescence with hepatic marker genes. Isolated primary hepatocytes were printed with alginate. The 3D printed hepatocytes remained alive for 14 days. Gene expression levels of Albumin , HNF-4α and Foxa3 were gradually increased in the 3D structures. Immunofluorescence analysis showed that the primary hepatocytes produced hepatic-specific proteins over the same period of time. Our research indicates that 3D bio-printing technique can be used for long-term culture of primary hepatocytes. It can therefore be used for drug screening and as a potential method of producing artificial livers.

Multiplex electrochemical DNA platform for femtomolar-level quantification of genetically modified soybean.

PubMed

Manzanares-Palenzuela, C Lorena; de-Los-Santos-Álvarez, Noemí; Lobo-Castañón, María Jesús; López-Ruiz, Beatriz

2015-06-15

Current EU regulations on the mandatory labeling of genetically modified organisms (GMOs) with a minimum content of 0.9% would benefit from the availability of reliable and rapid methods to detect and quantify DNA sequences specific for GMOs. Different genosensors have been developed to this aim, mainly intended for GMO screening. A remaining challenge, however, is the development of genosensing platforms for GMO quantification, which should be expressed as the number of event-specific DNA sequences per taxon-specific sequences. Here we report a simple and sensitive multiplexed electrochemical approach for the quantification of Roundup-Ready Soybean (RRS). Two DNA sequences, taxon (lectin) and event-specific (RR), are targeted via hybridization onto magnetic beads. Both sequences are simultaneously detected by performing the immobilization, hybridization and labeling steps in a single tube and parallel electrochemical readout. Hybridization is performed in a sandwich format using signaling probes labeled with fluorescein isothiocyanate (FITC) or digoxigenin (Dig), followed by dual enzymatic labeling using Fab fragments of anti-Dig and anti-FITC conjugated to peroxidase or alkaline phosphatase, respectively. Electrochemical measurement of the enzyme activity is finally performed on screen-printed carbon electrodes. The assay gave a linear range of 2-250 pM for both targets, with LOD values of 650 fM (160 amol) and 190 fM (50 amol) for the event-specific and the taxon-specific targets, respectively. Results indicate that the method could be applied for GMO quantification below the European labeling threshold level (0.9%), offering a general approach for the rapid quantification of specific GMO events in foods. Copyright © 2015 Elsevier B.V. All rights reserved.

SU-E-T-455: Characterization of 3D Printed Materials for Proton Beam Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou, W; Siderits, R; McKenna, M

2014-06-01

Purpose: The widespread availability of low cost 3D printing technologies provides an alternative fabrication method for customized proton range modifying accessories such as compensators and boluses. However the material properties of the printed object are dependent on the printing technology used. In order to facilitate the application of 3D printing in proton therapy, this study investigated the stopping power of several printed materials using both proton pencil beam measurements and Monte Carlo simulations. Methods: Five 3–4 cm cubes fabricated using three 3D printing technologies (selective laser sintering, fused-deposition modeling and stereolithography) from five printers were investigated. The cubes were scannedmore » on a CT scanner and the depth dose curves for a mono-energetic pencil beam passing through the material were measured using a large parallel plate ion chamber in a water tank. Each cube was measured from two directions (perpendicular and parallel to printing plane) to evaluate the effects of the anisotropic material layout. The results were compared with GEANT4 Monte Carlo simulation using the manufacturer specified material density and chemical composition data. Results: Compared with water, the differences from the range pull back by the printed blocks varied and corresponded well with the material CT Hounsfield unit. The measurement results were in agreement with Monte Carlo simulation. However, depending on the technology, inhomogeneity existed in the printed cubes evidenced from CT images. The effect of such inhomogeneity on the proton beam is to be investigated. Conclusion: Printed blocks by three different 3D printing technologies were characterized for proton beam with measurements and Monte Carlo simulation. The effects of the printing technologies in proton range and stopping power were studied. The derived results can be applied when specific devices are used in proton radiotherapy.« less

Properties of screen printed electrocardiography smartware electrodes investigated in an electro-chemical cell

PubMed Central

2013-01-01

Background ECG (Electrocardiogram) measurements in home health care demands new sensor solutions. In this study, six different configurations of screen printed conductive ink electrodes have been evaluated with respect to electrode potential variations and electrode impedance. Methods The electrode surfaces consisted of a Ag/AgCl-based ink with a conduction line of carbon or Ag-based ink underneath. On top, a lacquer layer was used to define the electrode area and to cover the conduction lines. Measurements were performed under well-defined electro-chemical conditions in a physiologic saline solution. Results The results showed that all printed electrodes were stable and have a very small potential drift (less than 3 mV/30 min). The contribution to the total impedance was 2% of the set maximal allowed impedance (maximally 1 kΩ at 50 Hz), assuming common values of input impedance and common mode rejection ratio of a regular amplifier. Conclusion Our conclusions are that the tested electrodes show satisfying properties to be used as elements in a skin electrode design that could be suitable for further investigations by applying the electrodes on the skin. PMID:23827015

In-vitro evaluation of copper nanoparticles cytotoxicity on prostate cancer cell lines and their antioxidant, sensing and catalytic activity: One-pot green approach.

PubMed

Prasad, P Reddy; Kanchi, S; Naidoo, E B

2016-08-01

In this study, Broccoli green extract was reported as a green and environmental friendly precursor for the one-pot biosynthesis of copper nanoparticles. The synthesized nanoparticles were characterized by UV-vis, FTIR, TEM, DLS, XRD and cyclic voltammetry. The TEM and DLS results showed that the NPs are in spherical and monodispersed with an average particle size of ~4.8nm. The FTIR results confirmed the occurrence of bioactive functional groups that are responsible for reducing cupric sulphate to copper ions. The UV-vis spectrophotometry was used for catalytic reduction of 4-nitrophenol and its dynamic reaction in Britton-Robinson buffer solution. This catalytic activity was further supported with methylene blue and methyl red dyes degradation. The nanocatalyst can be recovered from the reaction mixture and reused many times with none vital loss of catalytic activity. The Broccoli green extract modified copper nanoparticles coated on screen printing electrode laid a new sensing platform and has an excellent electrocatalytic activity. Furthermore, surface modified CuNPs with Broccoli green extract exhibited no cytotoxicity at the concentration ranging from 0.5 to 1.5μM on the prostate cancer (PC-3) cell lines. The maximum scavenging % of Broccoli green extract modified CuNPs was found to be >70.50% at the concentration of 0.25mM against 1,1-diphenyl-2-picrylhydrazyl. Copyright © 2016 Elsevier B.V. All rights reserved.

Single-Step Incubation Determination of miRNAs in Cancer Cells Using an Amperometric Biosensor Based on Competitive Hybridization onto Magnetic Beads.

PubMed

Vargas, Eva; Povedano, Eloy; Montiel, Víctor Ruiz-Valdepeñas; Torrente-Rodríguez, Rebeca M; Zouari, Mohamed; Montoya, Juan José; Raouafi, Noureddine; Campuzano, Susana; Pingarrón, José M

2018-03-15

This work reports an amperometric biosensor for the determination of miRNA-21, a relevant oncogene. The methodology involves a competitive DNA-target miRNA hybridization assay performed on the surface of magnetic microbeads (MBs) and amperometric transduction at screen-printed carbon electrodes (SPCEs). The target miRNA competes with a synthetic fluorescein isothiocyanate (FITC)-modified miRNA with an identical sequence for hybridization with a biotinylated and complementary DNA probe (b-Cp) immobilized on the surface of streptavidin-modified MBs (b-Cp-MBs). Upon labeling, the FITC-modified miRNA attached to the MBs with horseradish peroxidase (HRP)-conjugated anti-FITC Fab fragments and magnetic capturing of the MBs onto the working electrode surface of SPCEs. The cathodic current measured at -0.20 V (versus the Ag pseudo-reference electrode) was demonstrated to be inversely proportional to the concentration of the target miRNA. This convenient biosensing method provided a linear range between 0.7 and 10.0 nM and a limit of detection (LOD) of 0.2 nM (5 fmol in 25 μL of sample) for the synthetic target miRNA without any amplification step. An acceptable selectivity towards single-base mismatched oligonucleotides, a high storage stability of the b-Cp-MBs, and usefulness for the accurate determination of miRNA-21 in raw total RNA (RNA t ) extracted from breast cancer cells (MCF-7) were demonstrated.

A probe for NADH and H2O2 amperometric detection at low applied potential for oxidase and dehydrogenase based biosensor applications.

PubMed

Ricci, Francesco; Amine, Aziz; Moscone, Danila; Palleschi, Giuseppe

2007-01-15

Modified screen-printed electrodes for amperometric detection of H(2)O(2) and nicotinamide adenine dinucleotide (NADH) at low applied potential are presented in this paper. The sensors are obtained by modifying the working electrode surface with Prussian Blue, a well known electrochemical mediator for H(2)O(2) reduction. The coupling of this sensor with phenazine methosulfate (PMS) in the working solution gives the possibility of measuring both NAD(P)H and H(2)O(2). PMS reacts with NADH producing PMSH, which in the presence of oxygen, gives an equimolar amount of H(2)O(2). This allows the measurement of both analytes with similar sensitivity (357 mA mol(-1)L cm(-2) for H(2)O(2) and 336 mA mol(-1)L cm(-2) for NADH) and LOD (5x10(-7)mol L(-1) for H(2)O(2) and NADH) and opens the possibility of a whole series of biosensor applications. In this paper, results obtained with a variety of dehydrogenase enzymes (alcohol, malic, lactate, glucose, glycerol and glutamate) for the detection of enzymatic substrates or enzymatic activity are presented demonstrating the suitability of the proposed method for future biosensor applications.

Diazonium-protein adducts for graphite electrode microarrays modification: direct and addressed electrochemical immobilization.

PubMed

Corgier, Benjamin P; Marquette, Christophe A; Blum, Loïc J

2005-12-28

Diazonium cation electrodeposition was investigated for the direct and electro-addressed immobilization of proteins. For the first time, this reaction was triggered directly onto diazonium-modified proteins. Screen-printed (SP) graphite electrode microarrays were studied as active support for this immobilization. A 10-microelectrode (eight working electrodes, 0.2 mm2 each; one reference; and one auxiliary) setup was used to study the addressing possibilities of the method. These electrode microarrays were shown to be able to covalently graft diazonium cations through electrochemical reduction. Cyclic voltammetry and X-ray photoelectron spectroscopy were used to characterize the electrochemical grafting onto our SP graphite surface and suggested that a diazonium monolayer was deposited. Rabbit and human immunoglobulins (IgGs) were then chemically coupled to an aniline derivative (4-carboxymethylaniline), followed by diazotation to form an aryl diazonium function available for the electrodeposition. These modified proteins were both successfully electro-addressed at the surface of the graphite electrodes without cross-talk or interference. The immuno-biochip obtained using this novel approach enabled the specific detection of anti-rabbit IgG antibodies with a detection limit of 50 fmol of protein. A promising strategy to immobilize markedly different biological entities was then presented, providing an excellent spatial specificity of the electro-addressing.

Inkjet Printing of Amphotericin B onto Biodegradable Microneedles Using Piezoelectric Inkjet Printing

NASA Astrophysics Data System (ADS)

Boehm, Ryan D.; Miller, Philip R.; Schell, Wiley A.; Perfect, John R.; Narayan, Roger J.

2013-04-01

The delivery of amphotericin B, a pharmacologic agent with activity against a broad spectrum of fungi as well as against parasitic protozoa, has been complicated by the fact that amphotericin B exhibits poor solubility in aqueous solutions at physiologic pH levels. In this study, piezoelectric inkjet printing was used to modify the surfaces of Gantrez 169 BF microneedles (Ashland, Covington, KY). These amphotericin B-loaded microneedles demonstrated activity against Candida parapsilosis in a radial diffusion assay. The results of this study suggest that a combination of visible light dynamic mask microstereolithography, micromolding, and piezoelectric inkjet printing may be used to prepare amphotericin B-loaded microneedles with antifungal properties. It is envisioned that microneedles containing amphotericin B may be used for transdermal delivery of pharmacologic agents for the treatment of cutaneous fungal infections as well as cutaneous leishmaniasis.

Streamlined, Inexpensive 3D Printing of the Brain and Skull.

PubMed

Naftulin, Jason S; Kimchi, Eyal Y; Cash, Sydney S

2015-01-01

Neuroimaging technologies such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) collect three-dimensional data (3D) that is typically viewed on two-dimensional (2D) screens. Actual 3D models, however, allow interaction with real objects such as implantable electrode grids, potentially improving patient specific neurosurgical planning and personalized clinical education. Desktop 3D printers can now produce relatively inexpensive, good quality prints. We describe our process for reliably generating life-sized 3D brain prints from MRIs and 3D skull prints from CTs. We have integrated a standardized, primarily open-source process for 3D printing brains and skulls. We describe how to convert clinical neuroimaging Digital Imaging and Communications in Medicine (DICOM) images to stereolithography (STL) files, a common 3D object file format that can be sent to 3D printing services. We additionally share how to convert these STL files to machine instruction gcode files, for reliable in-house printing on desktop, open-source 3D printers. We have successfully printed over 19 patient brain hemispheres from 7 patients on two different open-source desktop 3D printers. Each brain hemisphere costs approximately $3-4 in consumable plastic filament as described, and the total process takes 14-17 hours, almost all of which is unsupervised (preprocessing = 4-6 hr; printing = 9-11 hr, post-processing = <30 min). Printing a matching portion of a skull costs $1-5 in consumable plastic filament and takes less than 14 hr, in total. We have developed a streamlined, cost-effective process for 3D printing brain and skull models. We surveyed healthcare providers and patients who confirmed that rapid-prototype patient specific 3D models may help interdisciplinary surgical planning and patient education. The methods we describe can be applied for other clinical, research, and educational purposes.

Development of high dispersed TiO2 paste for transparent screen-printable self-cleaning coatings on glass

NASA Astrophysics Data System (ADS)

Wang, Yuanhao; Lu, Lin; Yang, Hongxing; Che, Quande

2013-01-01

This paper reports a cheap and facile method to fabricate transparent self-cleaning coatings on glass by screen-printing high dispersed TiO2 paste. Three kinds of ZrO2 beads with diameter of 2, 1, and 0.1-0.2 mm were utilized to investigate their influence on the grinding and dispersion of the commercial TiO2 powder in the ball mill. From the SEM images, surface profiler and transmittance spectrum it could be demonstrated that the smallest ZrO2 bead with the diameter of 0.1-0.2 mm was the best candidate to disperse the TiO2 powder into nanoscale size to make the high dispersed TiO2 paste which was the key factor to achieve a smooth, high transparent TiO2 coating. The surface wettability measurement showed that all the screen-printed coatings had super hydrophilic surfaces, which was independent to the surface morphology. However, the coating with the highest transparency showed the lowest photocatalytic activity which is mainly due to the light loss.

The role of sustained attention and display medium in reading comprehension among adolescents with ADHD and without it.

PubMed

Stern, Pnina; Shalev, Lilach

2013-01-01

Difficulties in reading comprehension are common in children and adolescents with Attention Deficit/Hyperactivity Disorder (ADHD). The current study aimed at investigating the relation between sustained attention and reading comprehension among adolescents with and without ADHD. Another goal was to examine the impact of two manipulations of the text on the efficiency of reading comprehension: Spacing (standard- vs. double-spacing) and Type of presentation (computer screen vs. hard copy). Reading comprehension of two groups of adolescents (participants with ADHD and normal controls) was assessed and compared in four different conditions (standard printed, spaced printed, standard on computer screen, spaced on computer screen). In addition, participants completed a visual sustained attention task. Significant differences in reading comprehension and in sustained attention were obtained between the two groups. Also, a significant correlation was obtained between sustained attention and reading comprehension. Moreover, a significant interaction was revealed between presentation-type, spacing and level of sustained attention on reading comprehension. Implications for reading intervention and the importance of early assessment of attention functioning are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Digital multicolor printing: state of the art and future challenges

NASA Astrophysics Data System (ADS)

Kipphan, Helmut

1995-04-01

During the last 5 years, digital techniques have become extremely important in the graphic arts industry. All sections in the production flow for producing multicolor printed products - prepress, printing and postpress - are influenced by digitalization, in an evolutionary and revolutionary way. New equipment and network techniques bring all the sections closer together. The focus is put on high-quality multicolor printing, together with high productivity. Conventional offset printing technology is compared with the leading nonimpact printing technologies. Computer to press is contrasted with computer to print techniques. The newest available digital multicolor presses are described - the direct imaging offset printing press from HEIDELBERG with new laser imaging technique as well as the INDIGO and XEIKON presses based on electrophotography. Regarding technical specifications, economic calculations and print quality, it is worked out that each technique has its own market segments. An outlook is given for future computer to press techniques and the potential of nonimpact printing technologies for advanced high-speed multicolor computer to print equipment. Synergy effects from the NIP-technologies to the conventional printing technologies and vice versa are possible for building up innovative new products, for example hybrid printing systems. It is also shown that there is potential for improving the print quality, based on special screening algorithms, and a higher number of grey levels per pixel by using NIP-technologies. As an intermediate step in digitalization of the production flow, but also as an economical solution computer to plate equipment is described. By producing printed products totally in a digital way, digital color proofing as well as color management systems are needed. The newest high-tech equipment using NIP-technologies for producing proofs is explained. All in all it is shown that the state of the art in digital multicolor printing has reached a very high level in technology, productivity and quality, but that there is still space for improvements and innovations. Manufacturers of equipment and producers of printed products can take part in a successful evolution-changes, chances and challenges must be recognized and considered for future orientated activities and investments.

Screening for Panic Disorder

MedlinePlus

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Fabrication of bimetallic microfluidic surface-enhanced Raman scattering sensors on paper by screen printing.

PubMed

Qu, Lu-Lu; Song, Qi-Xia; Li, Yuan-Ting; Peng, Mao-Pan; Li, Da-Wei; Chen, Li-Xia; Fossey, John S; Long, Yi-Tao

2013-08-20

Au-Ag bimetallic microfluidic, dumbbell-shaped, surface enhanced Raman scattering (SERS) sensors were fabricated on cellulose paper by screen printing. These printed sensors rely on a sample droplet injection zone, and a SERS detection zone at either end of the dumbbell motif, fabricated by printing silver nanoparticles (Ag NPs) and gold nanoparticles (Au NPs) successively with microscale precision. The microfluidic channel was patterned using an insulating ink to connect these two zones and form a hydrophobic circuit. Owing to capillary action of paper in the millimeter-sized channels, the sensor could enable self-filtering of fluids to remove suspended particles within wastewater without pumping. This sensor also allows sensitive SERS detection, due to advantageous combination of the strong surface enhancement of Ag NPs and excellent chemical stability of Au NPs. The SERS performance of the sensors was investigated by employing the probe rhodamine 6G, a limit of detection (LOD) of 1.1×10(-13)M and an enhancement factor of 8.6×10(6) could be achieved. Moreover, the dumbbell-shaped bimetallic sensors exhibited good stability with SERS performance being maintained over 14 weeks in air, and high reproducibility with less than 15% variation in spot-to-spot SERS intensity. Using these dumbbell-shaped bimetallic sensors, substituted aromatic pollutants in wastewater samples could be quantitatively analyzed, which demonstrated their excellent capability for rapid trace pollutant detection in wastewater samples in the field without pre-separation. Copyright © 2013 Elsevier B.V. All rights reserved.

Can missed breast cancer be recognized by regular peer auditing on screening mammography?

PubMed

Pan, Huay-Ben; Yang, Tsung-Lung; Hsu, Giu-Cheng; Chiang, Chia-Ling; Huang, Jer-Shyung; Chou, Chen-Pin; Wang, Yen-Chi; Liang, Huei-Lung; Lee, San-Kan; Chou, Yi-Hong; Wong, Kam-Fai

2012-09-01

This study was conducted to investigate whether detectable missed breast cancers could be distinguished from truly false negative images in a mammographic screening by a regular peer auditing. Between 2004 and 2007, a total of 311,193 free nationwide biennial mammographic screenings were performed for 50- to 69-year-old women in Taiwan. Retrospectively comparing the records in Taiwan's Cancer registry, 1283 cancers were detected (4.1 per 1000). Of the total, 176 (0.6 per 1000) initial mammographic negative assessments were reported to have cancers (128 traditional films and 48 laser-printed digital images). We selected 186 true negative films (138 traditional films and 48 laser-printed ones) as control group. These were seeded into 4815 films of 2008 images to be audited in 2009. Thirty-four auditors interpreted all the films in a single-blind, randomized, pair-control study. The performance of 34 auditors was analyzed by chi-square test. A p value of < 0.05 was considered significant. Eight (6 traditional and 2 digital films) of the 176 false negative films were not reported by the auditors (missing rate of 4.5%). Of this total, 87 false negatives were reassessed as positive, while 29 of the 186 true negatives were reassessed as positive, making the overall performance of the 34 auditors in interpreting the false negatives and true negatives a specificity of 84.4% and sensitivity of 51.8%. The specificity and sensitivity in traditional films and laser-printed films were 98.6% versus 43.8% and 41.8% versus 78.3%, respectively. Almost 42% of the traditional false negative films had positive reassessment by the auditors, showing a significant difference from the initial screeners (p < 0.001). The specificity of their reinterpretation of laser-printed films was obviously low. Almost 42% of the false negative traditional films were judged as missed cancers in this study. A peer auditing should reduce the probability of missed cancers. 2012 Published by Elsevier B.V

Electrochemical Quantification of the Antioxidant Capacity of Medicinal Plants Using Biosensors

PubMed Central

Rodríguez-Sevilla, Erika; Ramírez-Silva, María-Teresa; Romero-Romo, Mario; Ibarra-Escutia, Pedro; Palomar-Pardavé, Manuel

2014-01-01

The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr) using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA), cross-linking using glutaraldehyde (GA), and cross-linking using GA and human serum albumin (HSA); the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric evaluations, the apparent Michaelis-Menten constant, Km′, of each biosensor was evaluated while the respective charge transfer resistance, Rct, was assessed from impedance measurements. It was found that the SPE/Tyr/GA had the smallest Km′ (57 ± 7) μM and Rct values. This electrode also displayed both the lowest detection and quantification limits for catechol quantification. Using the SPE/Tyr/GA, the Trolox Equivalent Antioxidant Capacity (TEAC) was determined from infusions prepared with “mirto” (Salvia microphylla), “hHierba dulce” (Lippia dulcis) and “salve real” (Lippia alba), medicinal plants commonly used in Mexico. PMID:25111237

Electrochemical DNA biosensor for detection of porcine oligonucleotides using ruthenium(II) complex as intercalator label redox

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halid, Nurul Izni Abdullah; Hasbullah, Siti Aishah; Heng, Lee Yook

2014-09-03

A DNA biosensor detection of oligonucleotides via the interactions of porcine DNA with redox active complex based on the electrochemical transduction is described. A ruthenium(II) complex, [Ru(bpy){sub 2}(PIP)]{sup 2+}, (bpy = 2,2′bipyridine, PIP = 2-phenylimidazo[4,5-f[[1,10-phenanthroline]) as DNA label has been synthesized and characterized by 1H NMR and mass spectra. The study was carried out by covalent bonding immobilization of porcine aminated DNA probes sequences on screen printed electrode (SPE) modified with succinimide-acrylic microspheres and [Ru(bpy){sub 2}(PIP)]{sup 2+} was used as electrochemical redox intercalator label to detect DNA hybridization event. Electrochemical detection was performed by cyclic voltammetry (CV) and differential pulsemore » voltammetry (DPV) over the potential range where the ruthenium (II) complex was active. The results indicate that the interaction of [Ru(bpy){sub 2}(PIP)]{sup 2+} with hybridization complementary DNA has higher response compared to single-stranded and mismatch complementary DNA.« less

Electrochemical quantification of the antioxidant capacity of medicinal plants using biosensors.

PubMed

Rodríguez-Sevilla, Erika; Ramírez-Silva, María-Teresa; Romero-Romo, Mario; Ibarra-Escutia, Pedro; Palomar-Pardavé, Manuel

2014-08-08

The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr) using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA), cross-linking using glutaraldehyde (GA), and cross-linking using GA and human serum albumin (HSA); the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric evaluations, the apparent Michaelis-Menten constant, Km', of each biosensor was evaluated while the respective charge transfer resistance, Rct, was assessed from impedance measurements. It was found that the SPE/Tyr/GA had the smallest Km' (57 ± 7) µM and Rct values. This electrode also displayed both the lowest detection and quantification limits for catechol quantification. Using the SPE/Tyr/GA, the Trolox Equivalent Antioxidant Capacity (TEAC) was determined from infusions prepared with "mirto" (Salvia microphylla), "hHierba dulce" (Lippia dulcis) and "salve real" (Lippia alba), medicinal plants commonly used in Mexico.

Fabrication of Lab-on-Paper Using Porous Au-Paper Electrode: Application to Tumor Marker Electrochemical Immunoassays.

PubMed

Ge, Shenguang; Zhang, Yan; Yan, Mei; Huang, Jiadong; Yu, Jinghua

2017-01-01

A simple, low-cost, and sensitive electrochemical lab-on-paper assay is developed based on a novel gold nanoparticle modified porous paper working electrode for use in point-of-care testing (POCT). Electrochemical methods are introduced for lab-on-paper based on screen-printed paper electrodes. To further improve specificity, performance, and sensitivity for point-of-care testing, a novel porous Au-paper working electrode (Au-PWE) is designed for lab-on-paper using growth of an interconnected Au nanoparticle (NP) layer on the surface of cellulose fibers in order to enhance the conductivity of the paper sample zone and immobilize the primary antibodies (Ab1). With a sandwich-type immunoassay format, Pd-Au bimetallic nanoparticles possessing peroxidase-like activity are used as a matrix to immobilize secondary antibodies (Ab2) for rapid detection of targets. This lab-on-paper based immunodevice is applied to the diagnosis of a cancer biomarker in clinical serum samples.

Wearable salivary uric acid mouthguard biosensor with integrated wireless electronics.

PubMed

Kim, Jayoung; Imani, Somayeh; de Araujo, William R; Warchall, Julian; Valdés-Ramírez, Gabriela; Paixão, Thiago R L C; Mercier, Patrick P; Wang, Joseph

2015-12-15

This article demonstrates an instrumented mouthguard capable of non-invasively monitoring salivary uric acid (SUA) levels. The enzyme (uricase)-modified screen printed electrode system has been integrated onto a mouthguard platform along with anatomically-miniaturized instrumentation electronics featuring a potentiostat, microcontroller, and a Bluetooth Low Energy (BLE) transceiver. Unlike RFID-based biosensing systems, which require large proximal power sources, the developed platform enables real-time wireless transmission of the sensed information to standard smartphones, laptops, and other consumer electronics for on-demand processing, diagnostics, or storage. The mouthguard biosensor system offers high sensitivity, selectivity, and stability towards uric acid detection in human saliva, covering the concentration ranges for both healthy people and hyperuricemia patients. The new wireless mouthguard biosensor system is able to monitor SUA level in real-time and continuous fashion, and can be readily expanded to an array of sensors for different analytes to enable an attractive wearable monitoring system for diverse health and fitness applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Wearable salivary uric acid mouthguard biosensor with integrated wireless electronics

PubMed Central

Kim, Jayoung; Imani, Somayeh; de Araujo, William R.; Warchall, Julian; Valdés-Ramírez, Gabriela; Paixão, Thiago R.L.C.; Mercier, Patrick P.; Wang, Joseph

2016-01-01

This article demonstrates an instrumented mouthguard capable of non-invasively monitoring salivary uric acid (SUA) levels. The enzyme (uricase)-modified screen printed electrode system has been integrated onto a mouthguard platform along with anatomically-miniaturized instrumentation electronics featuring a potentiostat, microcontroller, and a Bluetooth Low Energy (BLE) transceiver. Unlike RFID-based biosensing systems, which require large proximal power sources, the developed platform enables real-time wireless transmission of the sensed information to standard smartphones, laptops, and other consumer electronics for on-demand processing, diagnostics, or storage. The mouthguard biosensor system offers high sensitivity, selectivity, and stability towards uric acid detection in human saliva, covering the concentration ranges for both healthy people and hyperuricemia patients. The new wireless mouthguard biosensor system is able to monitor SUA level in real-time and continuous fashion, and can be readily expanded to an array of sensors for different analytes to enable an attractive wearable monitoring system for diverse health and fitness applications. PMID:26276541

Data Link Test and Analysis System/ATCRBS Transponder Test System

DTIC Science & Technology

1990-05-01

cc pcinit() pcinit.cc plotdato( plotdat. cc plotmsgo( sumscrn *cc plotqueo( sumscrn. cc pmsg () pmsg.cc pr_head() prhead.cc Virt init() print.cc pw...The code data from the Decode Status word from hardware. 2 a data-> wind nm - The reply window that this data came from. mvarms) NAME mparms - Modify...character is entered. m5sg() NAME pmsg - Print error message. Source file - pmsg.cc. FUNCTION CALL pmsg (ecode, str) int ecode; /* Error code */ char

A bio-enabled maximally mild layer-by-layer Kapton surface modification approach for the fabrication of all-inkjet-printed flexible electronic devices

PubMed Central

Fang, Yunnan; Hester, Jimmy G. D.; Su, Wenjing; Chow, Justin H.; Sitaraman, Suresh K.; Tentzeris, Manos M.

2016-01-01

A bio-enabled, environmentally-friendly, and maximally mild layer-by-layer approach has been developed to surface modify inherently hydrophobic Kapton HN substrates to allow for great printability of both water- and organic solvent-based inks thus facilitating the full-inkjet-printing of flexible electronic devices. Different from the traditional Kapton surface modification approaches which are structure-compromising and use harsh conditions to target, and oxidize and/or remove part of, the surface polyimide of Kapton, the present Kapton surface modification approach targeted the surface electric charges borne by its additive particles, and was not only the first to utilize environmentally-friendly clinical biomolecules to build up a thin film of protamine-heparin complex on Kapton, but also the first to be conducted under minimally destructive and maximally mild conditions. Besides, for electrically charged ink particles, the present surface modification method can enhance the uniformity of the inkjet-printed films by reducing the “coffee ring effect”. As a proof-of-concept demonstration, reduced graphene oxide-based gas sensors, which were flexible, ultra-lightweight, and miniature-sized, were fully-inkjet-printed on surface modified Kapton HN films and tested for their sensitivity to dimethyl methylphosphonate (a nerve agent simulant). Such fabricated sensors survived a Scotch-tape peel test and were found insensitive to repeated bending to a small 0.5 cm radius. PMID:28008987

Comparative analysis of single-walled and multi-walled carbon nanotubes for electrochemical sensing of glucose on gold printed circuit boards.

PubMed

Alhans, Ruby; Singh, Anukriti; Singhal, Chaitali; Narang, Jagriti; Wadhwa, Shikha; Mathur, Ashish

2018-09-01

In the present work, a comparative study was performed between single-walled carbon nanotubes and multi-walled carbon nanotubes coated gold printed circuit board electrodes for glucose detection. Various characterization techniques were demonstrated in order to compare the modified electrodes viz. cyclic voltammetry, electrochemical impedance spectroscopy and chrono-amperometry. Results revealed that single-walled carbon nanotubes outperformed multi-walled carbon nanotubes and proved to be a better sensing interface for glucose detection. The single-walled carbon nanotubes coated gold printed circuit board electrodes showed a wide linear sensing range (1 mM to 100 mM) with detection limit of 0.1 mM with response time of 5 s while multi-walled carbon nanotubes coated printed circuit board gold electrodes showed linear sensing range (1 mM to 100 mM) with detection limit of 0.1 mM with response time of 5 s. This work provided low cost sensors with enhanced sensitivity, fast response time and reliable results for glucose detection which increased the affordability of such tests in remote areas. In addition, the comparative results confirmed that single-walled carbon nanotubes modified electrodes can be exploited for better amplification signal as compared to multi-walled carbon nanotubes. Copyright © 2018. Published by Elsevier B.V.

A bio-enabled maximally mild layer-by-layer Kapton surface modification approach for the fabrication of all-inkjet-printed flexible electronic devices

NASA Astrophysics Data System (ADS)

Fang, Yunnan; Hester, Jimmy G. D.; Su, Wenjing; Chow, Justin H.; Sitaraman, Suresh K.; Tentzeris, Manos M.

2016-12-01

A bio-enabled, environmentally-friendly, and maximally mild layer-by-layer approach has been developed to surface modify inherently hydrophobic Kapton HN substrates to allow for great printability of both water- and organic solvent-based inks thus facilitating the full-inkjet-printing of flexible electronic devices. Different from the traditional Kapton surface modification approaches which are structure-compromising and use harsh conditions to target, and oxidize and/or remove part of, the surface polyimide of Kapton, the present Kapton surface modification approach targeted the surface electric charges borne by its additive particles, and was not only the first to utilize environmentally-friendly clinical biomolecules to build up a thin film of protamine-heparin complex on Kapton, but also the first to be conducted under minimally destructive and maximally mild conditions. Besides, for electrically charged ink particles, the present surface modification method can enhance the uniformity of the inkjet-printed films by reducing the “coffee ring effect”. As a proof-of-concept demonstration, reduced graphene oxide-based gas sensors, which were flexible, ultra-lightweight, and miniature-sized, were fully-inkjet-printed on surface modified Kapton HN films and tested for their sensitivity to dimethyl methylphosphonate (a nerve agent simulant). Such fabricated sensors survived a Scotch-tape peel test and were found insensitive to repeated bending to a small 0.5 cm radius.

Making data matter: Voxel printing for the digital fabrication of data across scales and domains.

PubMed

Bader, Christoph; Kolb, Dominik; Weaver, James C; Sharma, Sunanda; Hosny, Ahmed; Costa, João; Oxman, Neri

2018-05-01

We present a multimaterial voxel-printing method that enables the physical visualization of data sets commonly associated with scientific imaging. Leveraging voxel-based control of multimaterial three-dimensional (3D) printing, our method enables additive manufacturing of discontinuous data types such as point cloud data, curve and graph data, image-based data, and volumetric data. By converting data sets into dithered material deposition descriptions, through modifications to rasterization processes, we demonstrate that data sets frequently visualized on screen can be converted into physical, materially heterogeneous objects. Our approach alleviates the need to postprocess data sets to boundary representations, preventing alteration of data and loss of information in the produced physicalizations. Therefore, it bridges the gap between digital information representation and physical material composition. We evaluate the visual characteristics and features of our method, assess its relevance and applicability in the production of physical visualizations, and detail the conversion of data sets for multimaterial 3D printing. We conclude with exemplary 3D-printed data sets produced by our method pointing toward potential applications across scales, disciplines, and problem domains.

Three-dimensional printed magnetophoretic system for the continuous flow separation of avian influenza H5N1 viruses.

PubMed

Wang, Yuhe; Li, Yanbin; Wang, Ronghui; Wang, Maohua; Lin, Jianhan

2017-04-01

As a result of the low concentration of avian influenza viruses in samples for routine screening, the separation and concentration of these viruses are vital for their sensitive detection. We present a novel three-dimensional printed magnetophoretic system for the continuous flow separation of the viruses using aptamer-modified magnetic nanoparticles, a magnetophoretic chip, a magnetic field, and a fluidic controller. The magnetic field was designed based on finite element magnetic simulation and developed using neodymium magnets with a maximum intensity of 0.65 T and a gradient of 32 T/m for dragging the nanoparticle-virus complexes. The magnetophoretic chip was designed by SOLIDWORKS and fabricated by a three-dimensional printer with a magnetophoretic channel for the continuous flow separation of the viruses using phosphate-buffered saline as carrier flow. The fluidic controller was developed using a microcontroller and peristaltic pumps to inject the carrier flow and the viruses. The trajectory of the virus-nanoparticle complexes was simulated using COMSOL for optimization of the carrier flow and the magnetic field, respectively. The results showed that the H5N1 viruses could be captured, separated, and concentrated using the proposed magnetophoretic system with the separation efficiency up to 88% in a continuous flow separation time of 2 min for a sample volume of 200 μL. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Environmental and risk screening for prioritizing pollution prevention opportunities in the U.S. printed wiring board manufacturing industry.

PubMed

Lam, Carl W; Lim, Seong-Rin; Schoenung, Julie M

2011-05-15

Modern manufacturing of printed wiring boards (PWBs) involves extensive use of various hazardous chemicals in different manufacturing steps such as board preparation, circuit design transfer, etching and plating processes. Two complementary environmental screening methods developed by the U.S. EPA, namely: (i) the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) and (ii) Risk-Screening Environmental Indicators (RSEI), are used to quantify geographic and chemical environmental impacts in the U.S. PWB manufacturing industry based on Toxics Release Inventory (TRI) data. Although the release weight percentages of industrial chemicals such as methanol, glycol ethers and dimethylformamide comprise the larger fraction of reported air and water emissions, results indicate that lead, copper and their compounds' releases correspond to the highest environmental impact from toxicity potentials and risk-screening scores. Combining these results with further knowledge of PWB manufacturing, select alternative chemical processes and materials for pollution prevention are discussed. Examples of effective pollution prevention options in the PWB industry include spent etchant recovery technologies, and process and material substitutions. In addition, geographic assessment of environmental burden highlights states where promotion of pollution prevention strategies and emissions regulations can have the greatest effect to curb the PWB industry's toxic release impacts. Copyright © 2011 Elsevier B.V. All rights reserved.

Accomplishing Equilibrium in ALSEP: Demonstrations of Modified Process Chemistry on 3-D Printed Enhanced Annular Centrifugal Contactors

DOE PAGES

Brown, M. Alex; Wardle, Kent E.; Lumetta, Gregg; ...

2016-12-01

Here, the major components of the modified ALSEP process have been demonstrated on a modified 2-cm annular centrifugal contactor with an enhanced mixing zone using stable fission products and radiotracers. The results show that by decreasing the pH of the minor actinide stripping solution, using HEDTA instead of DTPA, and increasing contact time, the process is very effective in separating americium from the lanthanides and the fission products.

Screening for Obsessive-Compulsive Disorder (OCD)

MedlinePlus

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