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  1. Artikel: Open-source do-it-yourself multi-color fluorescence smartphone microscopy.

    Sung, Yulung / Campa, Fernando / Shih, Wei-Chuan

    Biomedical optics express

    2017  Band 8, Heft 11, Seite(n) 5075–5086

    Abstract: Fluorescence microscopy is an important technique for cellular and microbiological investigations. Translating this technique onto a smartphone can enable particularly powerful applications such as on-site analysis, on-demand monitoring, and point-of- ... ...

    Abstract Fluorescence microscopy is an important technique for cellular and microbiological investigations. Translating this technique onto a smartphone can enable particularly powerful applications such as on-site analysis, on-demand monitoring, and point-of-care diagnostics. Current fluorescence smartphone microscope setups require precise illumination and imaging alignment which altogether limit its broad adoption. We report a multi-color fluorescence smartphone microscope with a single contact lens-like add-on lens and slide-launched total-internal-reflection guided illumination for three common tasks in investigative fluorescence microscopy: autofluorescence, fluorescent stains, and immunofluorescence. The open-source, simple and cost-effective design has the potential for do-it-yourself fluorescence smartphone microscopy.
    Sprache Englisch
    Erscheinungsdatum 2017-10-19
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ZDB-ID 2572216-5
    ISSN 2156-7085
    ISSN 2156-7085
    DOI 10.1364/BOE.8.005075
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  2. Artikel ; Online: Smartphone Nanocolorimetry for On-Demand Lead Detection and Quantitation in Drinking Water.

    Nguyen, Hoang / Sung, Yulung / O'Shaughnessy, Kelly / Shan, Xiaonan / Shih, Wei-Chuan

    Analytical chemistry

    2018  Band 90, Heft 19, Seite(n) 11517–11522

    Abstract: Lead ions ( ... ...

    Abstract Lead ions (Pb
    Mesh-Begriff(e) Chromates/chemistry ; Colorimetry/instrumentation ; Colorimetry/methods ; Drinking Water/analysis ; Lead/analysis ; Lead/chemistry ; Limit of Detection ; Metal Nanoparticles/chemistry ; Potassium Compounds/chemistry ; Smartphone ; Water Pollutants, Chemical/analysis
    Chemische Substanzen Chromates ; Drinking Water ; Potassium Compounds ; Water Pollutants, Chemical ; Lead (2P299V784P) ; potassium chromate(VI) (5P0R38CN2X) ; lead chromate (AA3229AOUS)
    Sprache Englisch
    Erscheinungsdatum 2018-09-14
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1508-8
    ISSN 1520-6882 ; 0003-2700
    ISSN (online) 1520-6882
    ISSN 0003-2700
    DOI 10.1021/acs.analchem.8b02808
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  3. Artikel: Smartphone Nanocolorimetry for On-Demand Lead Detection and Quantitation in Drinking Water

    Nguyen, Hoang / Kelly O’Shaughnessy / Wei-Chuan Shih / Xiaonan Shan / Yulung Sung

    Analytical chemistry. 2018 Sept. 02, v. 90, no. 19

    2018  

    Abstract: Lead ions (Pb2+) contamination in drinking water, a major source of lead poisoning to the general population, is typically detected by bulky and costly laboratory analytical instrument. A mobile analytical device for rapid Pb2+ sensing is a growing ... ...

    Abstract Lead ions (Pb2+) contamination in drinking water, a major source of lead poisoning to the general population, is typically detected by bulky and costly laboratory analytical instrument. A mobile analytical device for rapid Pb2+ sensing is a growing demand. Herein, we report smartphone nanocolorimetry (SNC) as a new technique to detect and quantify dissolved Pb2+ in drinking water. Specifically, we have employed a single-step sedimentation approach by mixing a controlled quantity of chromate ion (CrO42–) to react with Pb2+ containing solutions to form highly insoluble lead chromate (PbCrO4) nanoparticles as vivid yellow precipitates. This is followed by microscopic color detection and intensity quantitation at nanoscale level using dark-field smartphone microscopy. The sum of the intensity of yellow pixels bears a highly reproducible relationship with Pb2+ concentration between 1.37 and 175 ppb in deionized water and 5–175 ppb in city tap water. In contrast to traditional colorimetric techniques analyzing bulk color changes, SNC achieves unparalleled sensitivity by combining nanocolorimetry with dark-field microscopy and mobilized the metal ions detection by integrating the detection into the smartphone microscope platform. SNC is rapid and low-cost and has the potential to enable individual citizens to examine Pb2+ content in drinking water on-demand in virtually any environmental setting.
    Schlagwörter chromates ; color ; colorimetry ; lead ; lead poisoning ; metal ions ; microscopy ; mixing ; mobile telephones ; nanoparticles ; tap water
    Sprache Englisch
    Erscheinungsverlauf 2018-0902
    Umfang p. 11517-11522.
    Erscheinungsort American Chemical Society
    Dokumenttyp Artikel
    ZDB-ID 1508-8
    ISSN 1520-6882 ; 0003-2700
    ISSN (online) 1520-6882
    ISSN 0003-2700
    DOI 10.1021/acs.analchem.8b02808
    Datenquelle NAL Katalog (AGRICOLA)

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  4. Artikel ; Online: Modeling the surface of fast-cured polymer droplet lenses for precision fabrication.

    Sung, Yu-Lung / Garan, Jacob / Hu, Zhenyu / Shan, Xiaonan / Shih, Wei-Chuan

    Applied optics

    2019  Band 57, Heft 35, Seite(n) 10342–10347

    Abstract: Optical lenses with diameter in the millimeter range have found important commercial use in smartphone cameras. Although these lenses are typically made by molding, recent demonstration of fast-cured polymer droplets by inkjet printing has gained ... ...

    Abstract Optical lenses with diameter in the millimeter range have found important commercial use in smartphone cameras. Although these lenses are typically made by molding, recent demonstration of fast-cured polymer droplets by inkjet printing has gained interest for cost-effective smartphone microscopy. In this technique, the surface of a fast-cured polydimethylsiloxane droplet obtains dynamic equilibrium via the interplay of surface tension, gravity, thermalization, and a steep viscosity hike. The nature of surface formation involves multiple physical and chemical domains, which represent significant challenges in modeling with the Young-Laplace theory, assuming constant surface tension and viscosity. To overcome these challenges, we introduce the concept of effective surface tension, which allows fast-cured polymer droplets to be modeled as normal liquid droplets with constant viscosity.
    Sprache Englisch
    Erscheinungsdatum 2019-01-15
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1539-4522
    ISSN (online) 1539-4522
    DOI 10.1364/AO.57.010342
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  5. Artikel ; Online: Cellular retinoic acid binding protein 1 protects mice from high-fat diet-induced obesity by decreasing adipocyte hypertrophy.

    Lin, Yi-Wei / Park, Sung Wook / Lin, Yu-Lung / Burton, Frank H / Wei, Li-Na

    International journal of obesity (2005)

    2019  Band 44, Heft 2, Seite(n) 466–474

    Abstract: Objectives: Obesity, an emerging global health issue, involves numerous factors; understanding its underlying mechanisms for prevention and therapeutics is urgently needed. Cellular retinoic acid binding protein 1 (Crabp1) knockout (CKO) mice exhibit an ...

    Abstract Objectives: Obesity, an emerging global health issue, involves numerous factors; understanding its underlying mechanisms for prevention and therapeutics is urgently needed. Cellular retinoic acid binding protein 1 (Crabp1) knockout (CKO) mice exhibit an obese phenotype under normal diet (ND) feedings, which prompted us to propose that Crabp1 could play a role in modulating adipose tissue development/homeostasis. Studies were designed to elucidate the underlying mechanism of Crabp1's action in reducing obesity.
    Subjects/methods: In animal studies, 6 weeks old male wild type and CKO mice were fed with ND or high-fat diet (HFD) for 10 weeks. Body weight and food intake were regularly monitored. Glucose tolerance test and biological parameters of plasma (glucose and insulin levels) were measured after 10 weeks of ND vs. HFD feedings. Visceral adipose tissues were collected for histological and molecular analyses to determine affected signaling pathways. In cell culture studies, the 3T3L1 adipocyte differentiation model was used to examine and validate relevant signaling pathways.
    Results: CKO mice, compared to WT mice, gained more body weight, exhibited more elevated fasting plasma glucose levels, and developed more severe impaired glucose tolerance under both ND and HFD. Histological examination revealed readily increased adipocyte hypertrophy and adipose tissue inflammation under HFD feedings. In 3T3L1 adipocytes, Crabp1 silencing enhanced extracellular signal-regulated kinase 1/2 (ERK1/2) activation, accompanied by elevated markers and signaling pathways of lipid accumulation and adipocyte hypertrophy.
    Conclusions: This study identifies Crabp1's physiological role against the development of obesity. The protective function of CRABP1 is likely attributed to its classically proposed (canonical) activity as a trap for RA, which will reduce RA availability, thereby dampening RA-stimulated ERK1/2 activation and adipocyte hypertrophy. The results suggest Crabp1 as a potentially new therapeutic target in managing obesity and metabolic diseases.
    Mesh-Begriff(e) 3T3-L1 Cells ; Adipocytes/metabolism ; Adipocytes/pathology ; Adipose Tissue, White/metabolism ; Adipose Tissue, White/pathology ; Animals ; Diet, High-Fat/adverse effects ; Hypertrophy/metabolism ; Hypertrophy/pathology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Obesity/etiology ; Obesity/metabolism ; Receptors, Retinoic Acid/genetics ; Receptors, Retinoic Acid/metabolism
    Chemische Substanzen Receptors, Retinoic Acid ; retinoic acid binding protein I, cellular
    Sprache Englisch
    Erscheinungsdatum 2019-06-04
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 752409-2
    ISSN 1476-5497 ; 0307-0565
    ISSN (online) 1476-5497
    ISSN 0307-0565
    DOI 10.1038/s41366-019-0379-z
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  6. Artikel ; Online: Correction to: Cellular retinoic acid binding protein 1 protects mice from high-fat diet-induced obesity by decreasing adipocyte hypertrophy.

    Lin, Yi-Wei / Park, Sung Wook / Lin, Yu-Lung / Burton, Frank H / Wei, Li-Na

    International journal of obesity (2005)

    2019  Band 43, Heft 11, Seite(n) 2347

    Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper. ...

    Abstract An amendment to this paper has been published and can be accessed via a link at the top of the paper.
    Sprache Englisch
    Erscheinungsdatum 2019-09-14
    Erscheinungsland England
    Dokumenttyp Published Erratum
    ZDB-ID 752409-2
    ISSN 1476-5497 ; 0307-0565
    ISSN (online) 1476-5497
    ISSN 0307-0565
    DOI 10.1038/s41366-019-0449-2
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  7. Artikel: Ammonia vapor sensor based on CdSe/SiO₂ core–shell nanoparticles embedded in sol–gel matrix

    Sung, Ti-Wen / Lo, Yu-Lung

    Sensors & Actuators: B. Chemical. 2013 Nov., v. 188

    2013  

    Abstract: A high-performance ammonia vapor sensor is proposed comprising CdSe/SiO₂ core–shell nanoparticles embedded in a sol–gel matrix immobilized on the tip of an optical fiber. The experimental results show that the luminescence intensity of the CdSe/SiO₂ ... ...

    Abstract A high-performance ammonia vapor sensor is proposed comprising CdSe/SiO₂ core–shell nanoparticles embedded in a sol–gel matrix immobilized on the tip of an optical fiber. The experimental results show that the luminescence intensity of the CdSe/SiO₂ nanoparticles reduces significantly when exposed to ammonia vapor. The fluorescence quenching effect is thought to be caused by the adsorption of the ammonia molecules at the trapped sites on the surface of the CdSe quantum dots (QDs). In addition, the proposed sensor exhibits good linearity for ammonia vapor concentrations between 10 and 400ppm, and has a detection limit of as little as 1.2ppm. Moreover, the sensor has a response time of 6.1s when switching from pure N₂ to a mixed N₂–ammonia vapor and 942.2s when switching in the reverse direction. Importantly, the signal changes are fully reversible when switching repeatedly between the two gaseous environments. Overall, the results show that the proposed sensor has many key advantages compared to optical sensors based on organic sensitive dye, including a higher response (I₀/I), an improved chemical stability, and full reversibility.
    Schlagwörter adsorption ; ammonia ; detection limit ; fluorescence ; light intensity ; nanoparticles ; nitrogen ; quantum dots ; vapors
    Sprache Englisch
    Erscheinungsverlauf 2013-11
    Umfang p. 702-708.
    Erscheinungsort Elsevier B.V.
    Dokumenttyp Artikel
    ZDB-ID 1021505-0
    ISSN 0925-4005
    ISSN 0925-4005
    DOI 10.1016/j.snb.2013.07.040
    Datenquelle NAL Katalog (AGRICOLA)

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  8. Artikel ; Online: Fabricating optical lenses by inkjet printing and heat-assisted in situ curing of polydimethylsiloxane for smartphone microscopy.

    Sung, Yu-Lung / Jeang, Jenn / Lee, Chia-Hsiung / Shih, Wei-Chuan

    Journal of biomedical optics

    2015  Band 20, Heft 4, Seite(n) 47005

    Abstract: We present a highly repeatable, lithography-free and mold-free method for fabricating flexible optical lenses by in situ curing liquid polydimethylsiloxane droplets on a preheated smooth surface with an inkjet printing process. This method enables us to ... ...

    Abstract We present a highly repeatable, lithography-free and mold-free method for fabricating flexible optical lenses by in situ curing liquid polydimethylsiloxane droplets on a preheated smooth surface with an inkjet printing process. This method enables us to fabricate lenses with a focal length as short as 5.6 mm, which can be controlled by varying the droplet volume and the temperature of the preheated surface. Furthermore, the lens can be attached to a smartphone camera without any accessories and can produce high-resolution (1  μm) images for microscopy applications.
    Mesh-Begriff(e) Computer Peripherals ; Dimethylpolysiloxanes/chemistry ; Equipment Design ; Equipment Failure Analysis ; Hardness ; Heating ; Hot Temperature ; Image Enhancement/instrumentation ; Lenses ; Microscopy/instrumentation ; Printing, Three-Dimensional/instrumentation ; Reproducibility of Results ; Sensitivity and Specificity ; Smartphone/instrumentation
    Chemische Substanzen Dimethylpolysiloxanes ; baysilon (63148-62-9)
    Sprache Englisch
    Erscheinungsdatum 2015-04-14
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1309154-2
    ISSN 1560-2281 ; 1083-3668
    ISSN (online) 1560-2281
    ISSN 1083-3668
    DOI 10.1117/1.JBO.20.4.047005
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  9. Artikel ; Online: Automated batch characterization of inkjet-printed elastomer lenses using a LEGO platform.

    Sung, Yu-Lung / Garan, Jacob / Nguyen, Hoang / Hu, Zhenyu / Shih, Wei-Chuan

    Applied optics

    2017  Band 56, Heft 26, Seite(n) 7346–7350

    Abstract: Small, self-adhesive, inkjet-printed elastomer lenses have enabled smartphone cameras to image and resolve microscopic objects. However, the performance of different lenses within a batch is affected by hard-to-control environmental variables. We present ...

    Abstract Small, self-adhesive, inkjet-printed elastomer lenses have enabled smartphone cameras to image and resolve microscopic objects. However, the performance of different lenses within a batch is affected by hard-to-control environmental variables. We present a cost-effective platform to perform automated batch characterization of 300 lens units simultaneously for quality inspection. The system was designed and configured with LEGO bricks, 3D printed parts, and a digital camera. The scheme presented here may become the basis of a high-throughput, in-line inspection tool for quality control purposes and can also be employed for optimization of the manufacturing process.
    Sprache Englisch
    Erscheinungsdatum 2017-09-10
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1539-4522
    ISSN (online) 1539-4522
    DOI 10.1364/AO.56.007346
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  10. Artikel: Highly sensitive and selective sensor based on silica-coated CdSe/ZnS nanoparticles for Cu²⁺ ion detection

    Sung, Ti-Wen / Lo, Yu-Lung

    Sensors & Actuators: B. Chemical. 2012 Apr., v. 165, no. 1

    2012  

    Abstract: A high performance fiber-optic sensor for Cu²⁺ ions is proposed based on monodispersed hydrophobic CdSe/ZnS nanoparticles encapsulated within a silica shell and immobilized on the tip of an optical fiber by a polyvinyl alcohol (PVA) polymer coating. The ... ...

    Abstract A high performance fiber-optic sensor for Cu²⁺ ions is proposed based on monodispersed hydrophobic CdSe/ZnS nanoparticles encapsulated within a silica shell and immobilized on the tip of an optical fiber by a polyvinyl alcohol (PVA) polymer coating. The experimental results show that the core–shell CdSe/ZnS@SiO₂ nanostructure exhibits a strong reduction in luminescence intensity following interaction with Cu²⁺ ions. The porous silica shell of the nanostructure also plays a key role in the fluorescence quenching process by preventing the aggregation of the CdSe/ZnS nanoparticles; thereby promoting the adsorption of the Cu²⁺ ions. There were linear relationships between the relative fluorescence intensity (I₀/I) and the concentration for Cu²⁺ ions from 0 to 10μM (R²=0.9858). The resolution of this sensor detected by a commercial hand-held spectrometer was about 0.9μM and therefore it is an ideal solution for applications in chemical and medical detections. The use of a silica-coated CdSe/ZnS QD has a number of key advantages as compared to the organic ligand modified QDs, including better selectivity, higher sensitivity, better chemical stability, and more stable with wide pH value.
    Schlagwörter adsorption ; coatings ; copper ; fiber optics ; fluorescence ; hydrophobicity ; ions ; light intensity ; nanoparticles ; pH ; polyvinyl alcohol ; silica
    Sprache Englisch
    Erscheinungsverlauf 2012-04
    Umfang p. 119-125.
    Erscheinungsort Elsevier B.V.
    Dokumenttyp Artikel
    ZDB-ID 1021505-0
    ISSN 0925-4005
    ISSN 0925-4005
    DOI 10.1016/j.snb.2012.02.028
    Datenquelle NAL Katalog (AGRICOLA)

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