keyword
MENU ▼
Read by QxMD icon Read
search

Colorimetric

keyword
https://read.qxmd.com/read/30901291/expression-of-embryonic-stem-cell-markers-in-microcystic-lymphatic-malformation
#1
Elizabeth K Eady, Helen D Brasch, Jennifer de Jongh, Reginald W Marsh, Swee T Tan, Tinte Itinteang
AIM: To investigate the expression of embryonic stem cell (ESC) markers in microcystic lymphatic malformation (mLM). METHODS AND RESULTS: Cervicofacial mLM tissue samples from nine patients underwent 3,3'-diaminobenzidine (DAB) immunohistochemical (IHC) staining for ESC markers octamer-binding protein 4 (OCT4), homeobox protein NANOG, sex determining region Y-box 2 (SOX2), Krupple-like factor (KLF4), and proto-oncogene c-MYC. Transcriptional activation of these ESC markers was investigated using real-time polymerase chain reaction (RT-qPCR) and colorimetric in situ hybridization (CISH) on four and five of these mLM tissue samples, respectively...
March 22, 2019: Lymphatic Research and Biology
https://read.qxmd.com/read/30898725/comparison-of-five-methods-for-detection-of-carbapenemases-in-enterobacterales-with-proposal-of-a-new-algorithm
#2
Luis Lucena Baeza, Niels Pfennigwerth, Christopher Greissl, Stephan Göttig, Ahmad Saleh, Yvonne Stelzer, Sören G Gatermann, Axel Hamprecht
OBJECTIVES: The aim of this study was to evaluate the performance of five different carbapenemase tests and to develop an algorithm which will permit the detection of most common and rare carbapenemases in routine microbiology laboratories. MATERIALS AND METHODS: The immunochromatographic tests CARBA-5 (NG), RESIST-4 O.K.N.V. (Coris), the colorimetric β-CARBA (BioRad), a newly developed carbapenem-inactivation method (CIM) supplemented with zinc (zCIM) and the Xpert Carba-R (Cepheid) were challenged with a collection of 189 molecularly characterized Enterobacterales isolates, including 146 carbapenemase producers (CPE): VIM (n=48), OXA-48-like (n=40), NDM (n=29), KPC (n=13), IMI (n=9), IMP (n=9), OXA-58 (n=2) and GES (n=2)...
March 18, 2019: Clinical Microbiology and Infection
https://read.qxmd.com/read/30898078/gold-sensing-with-rhodamine-immobilized-hydrogel-based-colorimetric-sensor
#3
Sastiya Kampaengsri, Banchob Wanno, Thawatchai Tuntulani, Buncha Pulpoka, Chatthai Kaewtong
A highly sensitive and selective optical membrane for determination of Au3+ was synthesized by immobilization of a rhodamine derivative on agarose hydrogel. The sensing dye was synthesized by solvatochromism of rhodamine B via rhodamine lactone-zwitterion equilibrium. UV-vis spectroscopy, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were employed to confirm that the rhodamine-lactone (RhoL) was incorporated into the agarose hydrogel...
March 21, 2019: Environmental Technology
https://read.qxmd.com/read/30897427/novel-applications-of-perovskite-oxide-via-catalytic-peroxymonosulfate-advanced-oxidation-in-aqueous-systems-for-trace-l-cysteine-detection
#4
Lihong Liu, Jun Gao, Pengyun Liu, Xiaoguang Duan, Ning Han, Fuping Li, M Veronica Sofianos, Shaobin Wang, Xiaoyao Tan, Shaomin Liu
Perovskite oxides offer new opportunities in wastewater treatment via catalytic oxidation. Herein, we report a new application of perovskite oxides for biological detection via catalytic decolourisation and colorimetric determination. The presence of trace biomolecules in an aqueous system would interfere the decolourisation process of dyes, where the decolourisation rate is quantitatively correlated to the biomolecular concentration. In this work, trace L-cysteine (Cys) detection was demonstrated on the basis of a Ag-Ba0...
March 14, 2019: Journal of Colloid and Interface Science
https://read.qxmd.com/read/30896928/a-rapid-diagnostic-platform-for-colorimetric-differential-detection-of-dengue-and-chikungunya-viral-infections
#5
Ruisheng Wang, Serge Y Ongagna-Yhombi, Zhengda Lu, Elizabeth Centeno-Tablante, Susannah Colt, Xiangkun Elvis Cao, Yue Ren, Washington B Cárdenas, Saurabh Mehta, David Erickson
In this work, we demonstrate a rapid diagnostic platform with potential to transform clinical diagnosis of acute febrile illnesses in resource-limited settings. Acute febrile illnesses such as dengue and chikungunya, which pose high burdens of disease in tropical regions, share many nonspecific symptoms and are difficult to diagnose based on clinical history alone in the absence of accessible laboratory diagnostics. Through a unique color-mixing encoding and readout strategy, our platform enabled consistent and accurate multiplexed detection of dengue and chikungunya IgM/IgG antibodies in human clinical samples within 30 minutes...
March 21, 2019: Analytical Chemistry
https://read.qxmd.com/read/30896159/noble-metal-nanoparticle-based-multicolor-immunoassays-an-approach-toward-visual-quantification-of-the-analytes-with-the-naked-eye
#6
Xiaoming Ma, Shan He, Bin Qiu, Fang Luo, Longhua Guo, Zhenyu Lin
Noble metal nanoparticle-based colorimetric sensors have become powerful tools for the detection of different targets with convenient readout. Among the many types of nanomaterials, noble metal nanoparticles exhibit extraordinary optical responses mainly due to their excellent localized surface plasmon resonance (LSPR) properties. The absorption spectrum of the noble metal nanoparticles were mostly in the visible range. This property enables the visual detection of various analytes with the naked eye. Among numerous color change modes, the way that different concentrations of targets represent vivid color changes has brought to the forefront because the color distinction capability of normal human eyes are usually better than the intensity change...
March 21, 2019: ACS Sensors
https://read.qxmd.com/read/30895774/colorimetric-detection-of-salivary-%C3%AE-amylase-using-maltose-as-inhibitor-for-polysaccharide-cleavage
#7
Iuna Tsyrulneva, Alagappan Palaniappan, Bo Liedberg
This paper describes an approach for colorimetric detection of salivary α-amylase, one of the potential biomarkers of autonomic nervous system (ANS) activity, for enabling assessment of fatigue. The ability of α-amylase to cleave α-bonds of polysaccharides is utilized for developing a colorimetric assay. In the proposed approach, 2-chloro-4-nitrophenyl-α-D-maltotrioside as substrate releases a colored by-product upon cleavage by salivary α-amylase. Introduction of maltose as a non-competitive inhibitor yields desirable linear responses in the physiologically relevant concentration range (20-500 μg/mL) with a limit of detection (LOD) of 8 μg/mL (in aqueous solution)...
March 21, 2019: ACS Sensors
https://read.qxmd.com/read/30895111/mechanical-and-frictional-properties-of-aesthetic-orthodontic-wires-obtained-by-hard-chrome-carbide-plating
#8
Takashi Usui, Toshio Iwata, Shinjiro Miyake, Takero Otsuka, So Koizumi, Nobukazu Shirakawa, Toshitsugu Kawata
Background/purpose: Although aesthetic wire coating has been increasing in demand, it has problems that changes in mechanical properties and increase in frictional force. The aim of this study was to evaluate the coating of the wire, as characterized by aesthetics, in terms of low and constant friction and mechanical properties. Materials and methods: Hard chrome carbide-plated (HCCP) wires (HCCP group), commercially available polymer-coated wires (P group), rhodium-coated wires (R group), and uncoated wires (control group) were used...
June 2018: Journal of Dental Sciences
https://read.qxmd.com/read/30894647/development-of-a-13-c-stable-isotope-assay-for-dipeptidyl-peptidase-4-enzyme-activity-a-new-breath-test-for-dipeptidyl-peptidase-activity
#9
Roger Yazbeck, Simone Jaenisch, Michelle Squire, Catherine A Abbott, Emma Parkinson-Lawrence, Douglas A Brooks, Ross N Butler
Dipeptidyl peptidase-4 inhibitors (DPP4i) are a class of orally available, small molecule inhibitors for the management of Type-II diabetes. A rapid, real-time, functional breath test for DPP4 enzyme activity could help to define DPP4i efficacy in patients that are refractory to treatment. We aimed to develop a selective, non-invasive, stable-isotope 13 C-breath test for DPP4. In vitro experiments were performed using high (Caco-2) and low (HeLa) DPP4 expressing cells. DPP gene expression was determined in cell lines by qRT-PCR...
March 20, 2019: Scientific Reports
https://read.qxmd.com/read/30892867/colorimetric-detection-of-carcinogenic-alkylating-fumigants-on-nylon-6-nanofibrous-membrane-part-ii-self-catalysis-of-2-diethylaminoethyl-modified-sensor-matrix-for-improvement-of-sensitivity
#10
Peixin Tang, Ngoc Thi-Hong Nguyen, Jeane Gladys Lo, Gang Sun
Nylon 6 nanofibrous membrane (N6NFM) was covalently modified with 2-diethylaminoethylchloride (DEAE-Cl) to provide self-catalytic functions to facilitate the formation of color compounds in reactions of 4-( p-nitrobenzyl)pyridine with alkylating fumigants. The 2-diethylaminoethyl group on the DEAE-Cl modified N6NFM (DEAE@N6NFM) enables effective elimination of hydrohalogenic acids from intermediates that were formed from reactions between the alkylating fumigants and NBP, and consequently improve their detection sensitivities, especially for 1,3-dichloropropene at room temperature...
March 20, 2019: ACS Applied Materials & Interfaces
https://read.qxmd.com/read/30891901/interfacial-assembly-of-signal-amplified-multienzymes-and-biorecognized-antibody-into-proteinosome-for-an-ultrasensitive-immunoassay
#11
Xu Yan, Tingting Wang, Dong Yao, Jiayun Xu, Quan Luo, Junqiu Liu
Enzyme as signal tag has been widely employed in colorimetric immunoassays for decades. Nevertheless, it remains a great challenge to substantially improve the detection sensitivity of enzyme-based immunoassays, which inhibits further critical applications. To circumvent this confinement, a multifunctional self-assembled proteinosome based on the integration of signal amplification elements (enzyme) and biorecognition unit (antibody) is proposed for fabricating an immunoassay strategy with significantly enhanced sensitivity...
March 20, 2019: Small
https://read.qxmd.com/read/30889764/onsite-paper-type-colorimetric-detector-with-enhanced-sensitivity-for-alkali-ion-via-polydiacetylene-nanoporous-rice-husk-silica-composites
#12
Sinae Song, Hong-Baek Cho, Hong Woon Lee, Hee Taik Kim
A paper-type colorimetric detector for identifying the degree of alkali ion concentration with the naked eye was fabricated using polydiacetylene/nanoporous rice husk silica (PDA/NP-SiO2 ) nanocomposites as a potentially effective, rapid, and facile approach to detect alkali ion in aqueous solution. This study is worth investigating because it has the advantage of visually confirming the alkaline ion in aqueous solution without the aid of other analytical instruments directly at on-site as if pH indicator analysis...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
https://read.qxmd.com/read/30889739/chemosensing-properties-and-logic-gate-behaviors-of-graphene-quantum-dot-appended-terpyridine
#13
Si-Yuan Kang, Hong Yin, Kai-Qi Zhang, Xiaobo Chen, Ke-Zhi Wang
Graphene quantum dot-covalently appended terpyridine, GQDs-tpy, was synthesized and characterized by X-ray photoelectron spectroscopy, FTIR spectroscopy and transmission electron microscopy. GQDs-tpy was found to act as multifunctional chemosensors: a highly selective colorimetric chemosensor for Fe2+ as evidenced by an obvious color change from colorless to pink, and a typical fluorescence enhanced probe for Zn2+ over 13 metal cations even in practical water samples. Moreover, two-input XOR, INHIBIT and IMPICATION logic gates as well as four-input OR and NOR logic gates were constructed according to the characteristic responses of GQDs-tpy to a sequence of cations...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
https://read.qxmd.com/read/30889678/enzyme-mimetic-activities-of-spinel-substituted-nanoferrites-mfe-2-o-4-a-review-of-synthesis-mechanism-and-potential-applications
#14
REVIEW
Naz Chaibakhsh, Zeinab Moradi-Shoeili
Recently, the intrinsic enzyme-like activities of some nanoscale materials known as "nanozymes" have become a growing area of interest. Nanosized spinel substituted ferrites (SFs) with general formula of MFe2 O4 , where M represents a transition metal, are among a group of magnetic nanomaterials attracting researchers' enormous attention because of their excellent catalytic performance, biomedical applications and capability for environmental remediation. Due to their unique nanoscale physical-chemical properties, they have been used to mimic the catalytic activity of natural enzymes such as peroxidases, oxidases and catalases...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
https://read.qxmd.com/read/30888507/colorimetric-determination-of-lead-ii-or-mercury-ii-based-on-target-induced-switching-of-the-enzyme-like-activity-of-metallothionein-stabilized-copper-nanoclusters
#15
Ran Liu, Li Zuo, Xiaorong Huang, Shimeng Liu, Guiying Yang, Shiya Li, Changyin Lv
It is shown that metallothionein-stabilized copper nanoclusters (MT-CuNCs) display catalase-like activity. In the presence of either lead(II) or mercury(II), the catalase-like activity is converted to a peroxidase-like activity. On addition of Pb(II) or Hg(II), the inhibitory effect of MT-CuNCs on the chromogenic reaction of 3,3',5,5'-tetramethylbenzidine (TMB) with H2 O2 is weakened. On the other hand, the catalytic effect of the nanoclusters on the chromogenic reaction is increased. The system MT-CuNCs-Pb(II)/Hg(II) exhibits high affinity for the substrates TMB and H2 O2 ...
March 19, 2019: Mikrochimica Acta
https://read.qxmd.com/read/30885734/biocompatible-chitosan-based-hydrogel-with-tunable-mechanical-and-physical-properties-formed-at-body-temperature
#16
Ahmed A Nada, Eman A Ali, Ahmed A F Soliman
Chemical crosslinking hydrogels provide irreversible matrices with reliable characteristics for wider medical applications. When hydrogels used for hosting bioactive substances, matrices have to be crosslinked at mild condition with high yield reaction and inactive to the biological molecules. In this work, chitosan was functionalized with active double bonds as a precursor to hydrogel that gels at body temperature. Free-radical crosslinking was conducted in the presence of maleic anhydride (MA) and potassium persulfate (KPS)...
March 15, 2019: International Journal of Biological Macromolecules
https://read.qxmd.com/read/30884982/effects-of-anti-glaucoma-prostaglandin-ophthalmic-solutions-on-cultured-human-corneal-epithelial-cells
#17
Louis Tong, Eri Matsuura, Miki Takahashi, Takashi Nagano, Kouichi Kawazu
PURPOSE: We compare the cytotoxicity of anti-glaucoma prostaglandin ophthalmic solutions on human corneal epithelial cells, and elucidate mechanisms of toxicity. METHODS: Cell viability was examined using MTS assay, and morphological changes of the cells was observed. Induction of necrosis/apoptosis was measured by colorimetric caspase assay. The production of ROS and release of cytokines were analyzed using 2', 7'-dichlorodihydrofluorescein diacetate and bead-based indirect immunofluorescent assay, respectively...
March 18, 2019: Current Eye Research
https://read.qxmd.com/read/30884703/molecular-dynamics-of-starch-and-water-during-bread-making-monitored-with-temperature-controlled-time-domain-1-h-nmr
#18
Mieke A Nivelle, Alice S Beghin, Geertrui M Bosmans, Jan A Delcour
Time domain proton nuclear magnetic resonance (TD 1 H NMR) was applied in a temperature-controlled mode to in situ study the timing and extent of starch transitions and water redistribution during bread making. Changes in proton population areas during initial baking (≤ 60 °C) were attributed to water absorption by starch and some initial amylose leaching. During subsequent heating (60-90 °C), proton population areas changed because of amylopectin crystal melting and amylose leaching. Granule swelling and amylose leaching increased the system's viscosity and thereby decreased the proton mobility...
May 2019: Food Research International
https://read.qxmd.com/read/30884666/silver-and-gold-nanoparticles-based-colorimetric-assays-for-the-determination-of-sugars-and-polyphenols-in-apples
#19
Annalisa Scroccarello, Flavio Della Pelle, Lilia Neri, Paola Pittia, Dario Compagnone
In this work, the exploitability of rapid and easy to use methods for the evaluation of the antioxidant capacity (AOC) and sugars content (SC), through metal nanoparticles (MNPs) formation, has been proved and applied to apples. In particular, an AgNPs-based sugar quantification assays and an AuNPs-based polyphenols antioxidant capacity assay have been used as tools for the evaluation of apple extracts composition. Both assays are based on the ability of the analytes (sugars and polyphenols) to reduce the source of metal (Au3+ and Ag+ ), stabilizing, at the same time, the resulting MNPs colloidal suspensions...
May 2019: Food Research International
https://read.qxmd.com/read/30879229/a-carbon-dot-based-ratiometric-fluorometric-and-colorimetric-method-for-determination-of-ascorbic-acid-and-of-the-activity-of-ascorbic-acid-oxidase
#20
Yanying Wang, Yan Yang, Wei Liu, Fang Ding, Ping Zou, Xianxiang Wang, Qingbiao Zhao, Hanbing Rao
A dual-mode method was developed for the determination of ascorbic acid (AA) and of ascorbic acid oxidase (AA-Ox) activity. It combines the advantages of ratiometric fluorometry and colorimetry. The assay is based on the oxidation of o-phenylenediamine (OPDA) by permanganate (KMnO4 ). A yellow substance (referred to as oxOPDA) with an absorption peak at 425 nm is rapidly produced in the presence of the oxidant. oxOPDA reduces the blue fluorescence of carbon dots (C-dots) peaking at 450 nm (upon 380-nm excitation), and a new emission peak is found at 565 nm...
March 16, 2019: Mikrochimica Acta
keyword
keyword
169367
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"