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https://www.readbyqxmd.com/read/28919468/a-copper-based-enzyme-free-fluorescence-elisa-for-her2-detection
#1
Shiyu Tian, Ke Zeng, Aijun Yang, Qin Wang, Minghui Yang
We reported an enzyme-free ELISA to detect breast cancer biomarker human epidermal growth factor receptor 2 (HER2) in human serum samples. Instead of enzymes (such as horseradish peroxidase) used in traditional ELISA, CuO nanoparticles were utilized as the signal probe. Compared to traditional enzymes, CuO nanoparticles have the advantages of low cost and good stability. After dissolving CuO nanoparticles with acid, the Cu (II) ions generated catalyzed the reaction of o-phenylenediamine with ascorbic acid to produce fluorescent quinoxaline derivative molecules...
September 14, 2017: Journal of Immunological Methods
https://www.readbyqxmd.com/read/28918353/antitumor-platinum-iv-derivatives-of-carboplatin-and-the-histone-deacetylase-inhibitor-4-phenylbutyric-acid
#2
Awatif Rashed Z Almotairy, Valentina Gandin, Liam Morrison, Cristina Marzano, Diego Montagner, Andrea Erxleben
Five new platinum(IV) derivatives of carboplatin each incorporating the histone deacetylase inhibitor 4-phenylbutyrate in axial position were synthesized and characterized by (1)H and (195)Pt NMR spectroscopy, electrospray ionization mass spectrometry and elemental analysis, namely cis,trans-[Pt(CBDCA)(NH3)2(PBA)(OH)] (1), cis,trans-[Pt(CBDCA)(NH3)2(PBA)2] (2), cis,trans-[Pt(CBDCA)(NH3)2(PBA)(bz)] (3), cis,trans-[Pt(CBDCA)(NH3)2(PBA)(suc)] (4) and cis,trans-[Pt(CBDCA)(NH3)2)(PBA)(ac)] (5) (PBA=4-phenylbutyrate, CBDCA=1,1-cyclobutane dicarboxylate, bz=benzoate, suc=succinate and ac=acetate)...
September 10, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28917785/fluorescence-quenching-based-alkaline-phosphatase-activity-detection
#3
Yaqi Mei, Qiong Hu, Baojing Zhou, Yonghui Zhang, Minhui He, Ting Xu, Feng Li, Jinming Kong
Simple and fast detection of alkaline phosphatase (ALP) activity is of great importance for diagnostic and analytical applications. In this work, we report a turn-off approach for the real-time detection of ALP activity on the basis of the charge transfer induced fluorescence quenching of the Cu(BCDS)2(2-) (BCDS = bathocuproine disulfonate) probe. Initially, ALP can enzymatically hydrolyze the substrate ascorbic acid 2-phosphate to release ascorbic acid (AA). Subsequently, the AA-mediated reduction of the Cu(BCDS)2(2-) probe, which displays an intense photoluminescence band at the wavelength of 402nm, leads to the static quenching of fluorescence of the probe as a result of charge transfer...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28917707/amoebicidal-antimicrobial-and-in-vitro-ros-scavenging-activities-of-tunisian-rubus-ulmifolius-schott-methanolic-extract
#4
Soumaya Hajaji, Mohamed Amine Jabri, Ines Sifaoui, Atteneri López-Arencibia, María Reyes-Batlle, Fatma B'chir, Basilio Valladares, José E Pinero, Jacob Lorenzo-Morales, Hafidh Akkari
The present study aimed to evaluate the activity of methanolic extract of Rubus ulmifolius Schott against the Acanthamoeba castellani Neff Strain as well as its antioxidant and antimicrobial effects. The tested extract has a good amoebicidal activity with low IC50 (61.785 ± 1.322 μg/ml) and also has significant activity against both Gram-positive (S. aureus, S. agalactiae) and Gram-negative bacteria (E. coli, S. typhimurium) and against C. albicans. The inhibition zones diameters (IZD) and minimal inhibitory concentration (MIC) values were in the range of 22...
September 13, 2017: Experimental Parasitology
https://www.readbyqxmd.com/read/28917640/biotinylated-platinum-iv-complexes-designed-to-target-cancer-cells
#5
Jian Zhao, Wuyang Hua, Gang Xu, Shaohua Gou
Three biotinylated platinum(IV) complexes (1-3) were designed and synthesized. The resulting platinum(IV) complexes exhibited effective cytotoxicity against the tested cancer cell lines, especially complex 1, which was 2.0-9.6-fold more potent than cisplatin. These complexes were found to be rapidly reduced to their activated platinum(II) counterparts by glutathione or ascorbic acid under biologically relevant condition. Additional molecular docking studies revealed that the biotin moieties of all Pt(IV) complexes can effectively bind with the streptavidin through the noncovalent interactions...
August 26, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28916045/evaluation-of-fluorogenic-substrates-for-ni-co-ldhs-peroxidase-mimic-and-application-for-determination-of-inhibitory-effects-of-antioxidant
#6
Li Su, Xinai Yu, Yexi Cai, Puhua Kang, Wenjie Qin, Wenpei Dong, Guojiang Mao, Suling Feng
Nanomaterial-based peroxidase-mimetics are an emerging research field that promises to produce alternatives to horseradish peroxidase for a variety of applications. Generally, some peroxidase-mimetics substrates are used in acidic condition (pH ≤ 7). Then, it is necessary to screen some peroxidase-mimetics substrates suitable for basic condition because that some peroxidase-mimetics leached ions in acidic solution. In this paper, using Ni/Co layered double hydroxides (LDHs) as a nano-peroxidase mimic model, we evaluated three fluorogenic substrates suitable for basic condition though experimental conditions, reaction kinetic and glucose detection assay...
September 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28915397/alleviation-of-cadmium-toxicity-in-lemna-minor-by-exogenous-salicylic-acid
#7
Qianqian Lu, Tingting Zhang, Wei Zhang, Chunlei Su, Yaru Yang, Dan Hu, Qinsong Xu
Cadmium (Cd) is a significant environmental pollutant in the aquatic environment. Salicylic acid (SA) is a ubiquitous phenolic compound. The goal of this study was to assess the morphological, physiological and biochemical changes in duckweed (L. minor) upon exposure to 10μM CdCl2, 10μM CdCl2 plus 50μM SA, or 50μM SA for 7 days. Reversing the effects of Cd, SA decreased Cd accumulation in plants, improved accumulation of minerals (Ca, Mg, Fe, B, Mo) absorption, increased endogenous SA concentration, and phenylalanine ammonialyase (PAL) activity...
September 12, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28914997/synergistic-effect-of-l-ascorbic-acid-and-hyaluronic-acid-on-the-expressions-of-matrix-metalloproteinase-3-and-9-in-human-chondrocytes
#8
Teng-Le Huang, Che-Hua Yang, Goichi Yanai, Jo-Yu Liao, Shoichiro Sumi, Kai-Chiang Yang
Proinflammatory cytokines and reactive oxygen species (ROS) are known to be involved in the initiation and progression of osteoarthritis (OA). New evidence clarifying the correlation between ROS and inflammation has indicated that oxidative stress can up-regulate inflammatory cytokines. l-Ascorbic acid (AA), an antioxidant, has been shown to have anti-inflammatory effects and improve matrix deposition in chondrocytes. The purpose of this study was to examine the effects of hyaluronic acid (HA; 100 μg/mL) supplemented with AA (50 μg/mL) on human normal and interleukin-1 beta-stimulated (IL-1β, 10 ng/mL) chondrocytes...
September 15, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28911680/effect-of-storage-temperature-and-time-on-the-nutritional-quality-of-walnut-male-inflorescences
#9
Wen-E Zhang, Chang-Lei Wang, Bin-Bin Shi, Xue-Jun Pan
The objective of this study was to investigate the effect of storage temperature and time on nutrients, bioactive compounds, and antioxidant activities of walnut male inflorescences. The results showed that the moisture, saccharides, fat, protein, amino acids, ascorbic acid, phenolic and flavonoid compound contents, and antioxidant activities of walnut male inflorescences were markedly influenced by storage temperature, and different degrees of decrease in these parameters were observed during the entire storage period...
April 2017: Journal of Food and Drug Analysis
https://www.readbyqxmd.com/read/28911669/simultaneous-determination-of-ascorbic-acid-and-caffeine-in-commercial-soft-drinks-using-reversed-phase-ultraperformance-liquid-chromatography
#10
Fatma Turak, Remziye Güzel, Erdal Dinç
A new reversed-phase ultraperformance liquid chromatography method with a photodiode array detector was developed for the quantification of ascorbic acid (AA) and caffeine (CAF) in 11 different commercial drinks consisting of one energy drink and 10 ice tea drinks. Separation of the analyzed AA and CAF with an internal standard, caffeic acid, was performed on a Waters BEH C18 column (100 mm × 2.1 mm, 1.7 μm i.d.), using a mobile phase consisting of acetonitrile and 0.2M H3PO4 (11:89, v/v) with a flow rate of 0...
April 2017: Journal of Food and Drug Analysis
https://www.readbyqxmd.com/read/28911636/novel-electrochemical-xanthine-biosensor-based-on-chitosan-polypyrrole-gold-nanoparticles-hybrid-bio-nanocomposite-platform
#11
Muamer Dervisevic, Esma Dervisevic, Emre Çevik, Mehmet Şenel
The aim of this study was the electrochemical detection of the adenosine-3-phosphate degradation product, xanthine, using a new xanthine biosensor based on a hybrid bio-nanocomposite platform which has been successfully employed in the evaluation of meat freshness. In the design of the amperometric xanthine biosensor, chitosan-polypyrrole-gold nanoparticles fabricated by an in situ chemical synthesis method on a glassy carbon electrode surface was used to enhance electron transfer and to provide good enzyme affinity...
July 2017: Journal of Food and Drug Analysis
https://www.readbyqxmd.com/read/28911618/green-synthesis-of-silver-nanoparticles-using-onion-extract-and-their-application-for-the-preparation-of-a-modified-electrode-for-determination-of-ascorbic-acid
#12
Mohammad A Khalilzadeh, Mina Borzoo
A high-quality method for one-pot biosynthesis of silver nanoparticles (AgNPs) using onion extracts as reductant and stabilizer is reported. The synthesized AgNPs were characterized by ultraviolet-visible spectroscopy (UV-Vis), X-ray powder diffraction (XRD), and transmission electron microscopy (TEM). UV-Vis spectroscopy results showed that the AgNP absorption band was located at a peak of 397 nm in aqueous solution. Both XRD and TEM results confirmed that the AgNPs were mainly spherical with average diameters of 6...
October 2016: Journal of Food and Drug Analysis
https://www.readbyqxmd.com/read/28910323/comparative-proteomic-analyses-reveal-the-proteome-response-to-short-term-drought-in-italian-ryegrass-lolium-multiflorum
#13
Ling Pan, Zhongfu Yang, Jianping Wang, Pengxi Wang, Xiao Ma, Meiliang Zhou, Ji Li, Nie Gang, Guangyan Feng, Junming Zhao, Xinquan Zhang
Drought is a major abiotic stress that impairs growth and productivity of Italian ryegrass. Comparative analysis of drought responsive proteins will provide insight into molecular mechanism in Lolium multiflorum drought tolerance. Using the iTRAQ-based approach, proteomic changes in tolerant and susceptible lines were examined in response to drought condition. A total of 950 differentially accumulated proteins was found to be involved in carbohydrate metabolism, amino acid metabolism, biosynthesis of secondary metabolites, and signal transduction pathway, such as β-D-xylosidase, β-D-glucan glucohydrolase, glycerate dehydrogenase, Cobalamin-independent methionine synthase, glutamine synthetase 1a, Farnesyl pyrophosphate synthase, diacylglycerol, and inositol 1, 4, 5-trisphosphate, which might contributed to enhance drought tolerance or adaption in Lolium multiflorum...
2017: PloS One
https://www.readbyqxmd.com/read/28905708/williamwhitmania-taraxaci-gen-nov-sp-nov-a-proteolytic-anaerobe-with-a-novel-type-of-cytology-from-lake-untersee-in-antarctica-description-of-williamwhitmaniaceae-fam-nov-and-emendation-of-the-order-bacteroidales-krieg-2012
#14
Elena V Pikuta, Zhe Lyu, Richard B Hoover, Yuchen Liu, Nisha B Patel, Hans J Busse, Paul A Lawson
The proteolytic bacterium strain A7P-90mT was isolated from Lake Untersee, Antarctica. The anoxic water was collected from a perennially sealed (~100 millennia) glacial ice lake. Gram-stain-negative cells were 0.18-0.3×8.0-25.0 µm in size, straight, slender rods with unusual gliding motility by external, not previously reported, organelles named here as antiae. At the end of stationary phase of growth, spheroplasts were terminally formed and the cells resembled dandelions. After death, cells were helical...
September 14, 2017: International Journal of Systematic and Evolutionary Microbiology
https://www.readbyqxmd.com/read/28904079/ascorbic-acid-promotes-a-tgf%C3%AE-1-induced-myofibroblast-phenotype-switch
#15
Bram Piersma, Olaf Y Wouters, Saskia de Rond, Miriam Boersema, Rutger A F Gjaltema, Ruud A Bank
l-Ascorbic acid (AA), generally known as vitamin C, is a crucial cofactor for a variety of enzymes, including prolyl-3-hydroxylase (P3H), prolyl-4-hydroxylase (P4H), and lysyl hydroxylase (LH)-mediated collagen maturation. Here, we investigated whether AA has additional functions in the regulation of the myofibroblast phenotype, besides its function in collagen biosynthesis. We found that AA positively influences TGFβ1-induced expression of COL1A1, ACTA2, and COL4A1 Moreover, we demonstrated that AA promotes αSMA stress fiber formation as well as the synthesis and deposition of collagens type I and IV Additionally, AA amplified the contractile phenotype of the myofibroblasts, as seen by increased contraction of a 3D collagen lattice...
September 2017: Physiological Reports
https://www.readbyqxmd.com/read/28902622/functional-interaction-between-n-methyl-d-aspartate-receptor-and-ascorbic-acid-during-neuropathic-pain-induced-by-chronic-constriction-injury-of-the-sciatic-nerve
#16
Sepideh Saffarpour, Farinaz Nasirinezhad
BACKGROUND: Neuropathic pain is a chronic pain condition, which is resistant to therapy. Ascorbate was released because of the activation of glutaminergic neurons. Due to the important role of N-methyl-D-aspartate (NMDA) receptors in the pathophysiology of neuropathic pain, this study investigated the analgesic efficacy of ascorbic acid (AA) in neuropathic pain condition and the role of NMDA receptors in this effect. METHODS: For this purpose, adult male rats were randomly allocated to experimental groups (n=8 in each group)...
September 13, 2017: Journal of Basic and Clinical Physiology and Pharmacology
https://www.readbyqxmd.com/read/28901807/exogenous-ascorbic-acid-improves-defence-responses-of-sunflower-helianthus-annuus-exposed-to-multiple-stresses
#17
Armagan Kaya
Ascorbic acid is an important antioxidant that plays role both on growth and development and also stress response of the plant. The purpose of this study was to determine the effect of ascorbate on physiological and biochemical changes of sunflower that was exposed to multiple stresses. Chlorophyll and carotenoid contents decreased and glutathione, ascorbate and malondialdehyde contents as well as antioxidant enzyme activities increased for sunflower plant that was exposed to 50 mM NaCl and pendimethalin at different concentrations...
September 2017: Acta Biologica Hungarica
https://www.readbyqxmd.com/read/28900717/monitoring-of-oxidative-status-in-three-native-australian-species-during-cold-acclimation-and-cryopreservation
#18
Bryn Funnekotter, Louise Colville, Anja Kaczmarczyk, Shane R Turner, Eric Bunn, Ricardo L Mancera
Three wild species exhibited a significant reduction in antioxidants throughout the cryopreservation protocol, whilst the half-cell reduction potential became more oxidised. Antioxidant content recuperated in recovering shoot tips. Cryopreservation is the most efficient and cost-effective long-term storage solution for the conservation of a wide range of plant species and material. Changes in the levels of antioxidants during the process of cryopreservation are known to reduce post-cryogenic survival due to oxidative stress...
September 12, 2017: Plant Cell Reports
https://www.readbyqxmd.com/read/28898409/combined-effect-of-ultrasound-and-mild-temperatures-on-the-inactivation-of-e-coli-in-fresh-carrot-juice-and-changes-on-its-physicochemical-characteristics
#19
Prashant Raj Pokhrel, Daniela Bermúdez-Aguirre, Héctor E Martínez-Flores, M Guadalupe Garnica-Romo, Shyam Sablani, Juming Tang, Gustavo V Barbosa-Cánovas
The combination of ultrasound and mild temperatures to process fruits and vegetables juices is a novel approach that is showing promising results for microbial inactivation and preservation of bioactive compounds and sensory attributes. This study centers on investigating the inactivation of Escherichia coli (ATCC 11755) in carrot juice as a result of the combined effect of ultrasound (24 kHz frequency, 120 μm, and 400 W) with temperature (50, 54, and 58 °C) and processing time (0 to 10 min). In addition, the possible changes in physicochemical properties and the retention of bioactive compounds after processing were analyzed...
September 12, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28898093/synthesis-of-stable-citrate-capped-silver-nanoprisms
#20
Jason M Haber, Konstantin Sokolov
Citrate-stabilized silver nanoprisms (AgNPrs) can be easily functionalized using well-developed thiol based surface chemistry that is an important requirement for biosensor applications utilizing localized surface plasmon resonance (LSPR) and surface-enhanced Raman Scattering (SERS). Unfortunately, currently available protocols for synthesis of citrate-coated AgNPrs do not produce stable nanoparticles thus limiting their usefulness in biosensing applications. Here we address this problem by carrying out a systematic study of citrate-stabilized, peroxide-based synthesis of AgNPrs to optimize reaction conditions for production of stable and reproducible nanoprisms...
September 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
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