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https://www.readbyqxmd.com/read/27925415/utilization-of-red-light-emitting-cdte-nanoparticles-for-the-trace-level-detection-of-harmful-herbicides-in-adulterated-food-and-agricultural-crops
#1
Nilanjan Dey, Deepa Bhagat, Durgadas Cherukaraveedu, Santanu Bhattacharya
Red-light-emitting water-soluble semiconducting quantum dots (QDs) were synthesized by using a wide variety of commercially available thiol-type capping agents. QDs with a negatively charged nanosurface showed excellent selectivity for paraquat (PQ) at pH 7.4 over other commonly encountered pesticides/herbicides, including diquat (DQ). The presence of a 4,4'-bis-pyridinium unit in PQ enabled it to initiate long-range aggregation, thereby leading to the formation of nanostructures with excellent emission-quenching behavior...
November 7, 2016: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/27925281/effect-of-natural-organic-matter-on-the-photo-induced-toxicity-of-titanium-dioxide-tio2-nanoparticles
#2
Alexis M Wormington, Jason Coral, Matthew M Alloy, Carmen L Damare, Charles M Mansfield, Stephen J Klaine, Joseph H Bisesi, Aaron P Roberts
Nano-TiO2 is the most widely used form of nanoparticles in commercial industry, and come in two main configurations: rutile and anatase. Rutile TiO2 is used in UV screening applications, while anatase TiO2 crystals have a surface defect that makes them photoreactive. There are numerous reports in the literature of photo-induced toxicity to aquatic organisms following co-exposure to anatase nano-TiO2 and UV. All natural freshwater contains varying amounts of natural organic matter (NOM), which can drive UV attenuation and quench ROS in aquatic ecosystems...
December 7, 2016: Environmental Toxicology and Chemistry
https://www.readbyqxmd.com/read/27924439/fluorescence-quenching-of-two-coumarin-3-carboxylic-acids-by-trivalent-lanthanide-ions
#3
Lamine Cisse, Abdoulaye Djande, Martine Capo-Chichi, François Delattre, Adama Saba, Jean-Claude Brochon, Serguei Sanouski, Alphonse Tine, Jean-Jacques Aaron
The effects of various trivalent lanthanide ions (acetates of Ce(3+), Er(3+), Eu(3+), Nd(3+)) on the electronic absorption and fluorescence spectra of un-substituted coumarin-3-carboxylic acid (CCA) and 7-N,N-diethylamino-coumarin-3-carboxylic acid (DECCA) have been investigated in dimethylsulfoxide (DMSO) at room temperature. Depending on the lanthanide ion nature and concentration, significant spectral changes of absorption bands occurred for both coumarin derivatives. These spectral changes were attributed to the formation of ground-state complexes between the coumarin carboxylate derivatives and lanthanide ions...
December 6, 2016: Journal of Fluorescence
https://www.readbyqxmd.com/read/27921033/new-tools-to-study-contact-activation
#4
Steffen Rosén
The recent availability of a sensitive chromogenic method approach for determination of FXIa activity has been explored for designing sensitive methods for FXIIa and kallikrein, both using FXa formation as the read-out. For both enzymes the assay range 1-10 nmol/L provides a resolution of about 0.8 absorbance units with a total assay time of about 20 min. For studies on activation kinetics, subsampling and extensive dilution can be performed in MES-bovine serum albumin (BSA) buffer pH 5.7 for quenching of enzyme activity and with ensuing determination of FXa generation in a chromogenic FXIa method...
2016: Frontiers in Medicine
https://www.readbyqxmd.com/read/27919227/high-light-stress-triggers-distinct-proteomic-responses-in-the-marine-diatom-thalassiosira-pseudonana
#5
Hong-Po Dong, Yue-Lei Dong, Lei Cui, Srinivasan Balamurugan, Jian Gao, Song-Hui Lu, Tao Jiang
BACKGROUND: Diatoms are able to acclimate to frequent and large light fluctuations in the surface ocean waters. However, the molecular mechanisms underlying these acclimation responses of diaotms remain elusive. RESULTS: In this study, we investigated the mechanism of high light protection in marine diatom Thalassiosira pseudonana using comparative proteomics in combination with biochemical analyses. Cells treated under high light (800 μmol photons m(-2)s(-1)) for 10 h were subjected to proteomic analysis...
December 5, 2016: BMC Genomics
https://www.readbyqxmd.com/read/27917701/design-synthesis-mtt-assay-dna-interaction-studies-of-platinum-ii-complexes
#6
Miral V Lunagariya, Khyati P Thakor, Bhargav N Waghela, Foram U Vaidya, Chadramani Pathak, Mohan N Patel
The square planar Pt(II) complexes of the type [Pt(L(n))(Cl2)] (where L(n) = L(1-3) = thiophene-2-carboxamide derivatives and L(4-6) = thiophene-2-carbothioamide derivatives) have been synthesized and characterized by physicochemical and various spectroscopic studies. MIC method was employed to inference the antibacterial potency of complexes in reference to free ligands and metal salt. Characteristic binding constant (Kb) and binding mode of complexes with calf thymus DNA (CT-DNA) were determined using absorption titration (0...
December 4, 2016: Journal of Biomolecular Structure & Dynamics
https://www.readbyqxmd.com/read/27917419/polyurethanes-with-aggregation-enhanced-emission-characteristics-preparation-and-properties
#7
Kun Wang, Jiping Yang, Chen Gong, Hao Lu
An amino-terminated poly(propylene glycol)-modified tetraaryl-buta-1,3-diene derivative (TABDAA) was introduced to synthesize polyurethanes with different ratios of soft/hard segments. A mixture of TABDAA and poly(tetrahydrofuran) 1000 as the soft segments was reacted with 4,4-diphenylmethane diisocyanate and 1,4-butanediol as the hard segments in molar ratios of 1 : 2 : 1, 2 : 3 : 1, and 3 : 4 : 1 to give the desired polyurethanes named TMPU-211, TMPU-321 and TMPU-431, respectively...
December 5, 2016: Faraday Discussions
https://www.readbyqxmd.com/read/27917100/synthesis-of-st7612aa1-a-novel-oral-hdac-inhibitor-via-radical-%C3%A2-thioacetic-acid-addition
#8
Gianfranco Battistuzzi, Giuseppe Giannini
ABSTRACT BACKGROUND: In the expanding field of anticancer drugs, HDAC inhibitors are playing an increasingly important role. To date, four/five HDAC inhibitors have been approved by FDA. All these compounds fit the widely accepted HDAC inhibitors pharmacophore model characterized by a cap group, a linker chain and a zinc binding group (ZBG), able to bind the Zn(2+) ion in a pocket of the HDAC active site. Romidepsin, a natural compound, is the only thiol derivative. We have selected a new class of synthetic HDAC inhibitors, the thio-ω(lactam-carboxamide) derivatives, with ST7612AA1 as drug candidate, pan-inhibitor active in the range of single- to two-digit nanomolar concentrations...
December 2016: Current Bioactive Compounds
https://www.readbyqxmd.com/read/27916897/investigation-on-fluorescence-quenching-mechanism-of-perylene-diimide-dyes-by-graphene-oxide
#9
Yuzhen Zhao, Kexuan Li, Zemin He, Yongming Zhang, Yang Zhao, Haiquan Zhang, Zongcheng Miao
Perylene diimide derivatives were used as probes to investigate the effect of the molecular structures on the fluorescence quenching mechanism in a perylene diimide/graphene oxide system. The electrons transferred from the excited state of dyes to the conductive band of graphene oxide with different concentrations were determined by fluorescence spectra. The results indicated that the quenching efficiency of perylene diimides by graphene oxide was not only dependent on the difference between the lowest unoccupied molecular orbital level of dyes and the conduction band of the graphene oxide, but also mainly on the difference in the molecular structures...
November 30, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27914369/dna-tetrahedral-scaffolds-based-platform-for-the-construction-of-electrochemiluminescence-biosensor
#10
Qiu-Mei Feng, Zhen Zhou, Mei-Xing Li, Wei Zhao, Jing-Juan Xu, Hong-Yuan Chen
Proximal metallic nanoparticles (NPs) could quench the electrochemiluminescence (ECL) emission of semiconductor quantum dots (QDs) due to Förster energy transfer (FRET), but at a certain distance, the coupling of light-emission with surface plasmon resonance (SPR) result in enhanced ECL. Thus, the modification strategies and distances control between QDs and metallic NPs are critical for the ECL intensity of QDs. In this strategy, a SPR enhanced ECL sensor based on DNA tetrahedral scaffolds modified platform was reported for the detection of telomerase activity...
November 27, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27914257/photosensitized-degradation-of-acetaminophen-in-natural-organic-matter-solutions-the-role-of-triplet-states-and-oxygen
#11
Yanyun Li, Yanheng Pan, Lushi Lian, Shuwen Yan, Weihua Song, Xin Yang
The photolysis of acetaminophen, a widely used pharmaceutical, in simulated natural organic matter solutions was investigated. The triplet states of natural organic matter ((3)NOM*) were found to play the dominant role in its photodegradation, while the contributions from hydroxyl radicals and singlet oxygen were negligible. Dissolved oxygen (DO) plays a dual role. From anaerobic to microaerobic (0.5 mg/L DO) conditions, the degradation rate of acetaminophen increased by 4-fold. That suggests the involvement of DO in reactions with the degradation intermediates...
November 22, 2016: Water Research
https://www.readbyqxmd.com/read/27913102/membrane-permeabilization-induced-by-triton-x-100-the-role-of-membrane-phase-state-and-edge-tension
#12
Bruno Mattei, Rafael B Lira, Katia R Perez, Karin A Riske
Detergents are widely used to solubilize and separate biomembrane components. It is therefore relevant to study and understand the mechanistic details underlying detergent-lipid interactions using biomimetic systems. Here, we have investigated in detail the process of membrane permeabilization and the nature of pores induced by sub-solubilizing concentrations of the detergent Triton X-100 (TX-100) in bilayers composed of palmitoyl oleoyl phosphatidylcholine (POPC), sphingomyelin (SM) and binary mixtures of these phospholipids with 30 mol% cholesterol (chol)...
November 29, 2016: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/27911925/attenuation-of-quorum-sensing-regulated-virulence-of-pectobacterium-carotovorum-subsp-carotovorum-through-an-ahl-lactonase-produced-by-lysinibacillus-sp-gs50
#13
Sneha S Garge, Anuradha S Nerurkar
Quorum sensing (QS) is a mechanism in which Gram negative bacterial pathogens sense their population density through acyl homoserine lactones (AHLs) and regulate the expression of virulence factors. Enzymatic degradation of AHLs by lactonases, known as quorum quenching (QQ), is thus a potential strategy for attenuating QS regulated bacterial infections. We characterised the QQ activity of soil isolate Lysinibacillus sp. Gs50 and explored its potential for controlling bacterial soft rot of crop plants. Lysinibacillus sp...
2016: PloS One
https://www.readbyqxmd.com/read/27910603/investigation-on-quench-initiation-and-propagation-characteristics-of-gdbco-coil-co-wound-with-a-stainless-steel-tape-as-turn-to-turn-metallic-insulation
#14
Y G Kim, J B Song, Y H Choi, D G Yang, S G Kim, H G Lee
This paper investigates the quench initiation and propagation characteristics of a metallic insulation (MI) coil by conducting thermal quench tests for a GdBCO single-pancake coil co-wound with a stainless steel tape as the turn-to-turn MI. The test results confirmed that the MI coil exhibited superior thermal and electrical stabilities compared to the conventional coils co-wound with organic insulation material because the operating current could flow along the radial direction due to the existence of a turn-to-turn contact when a local hot spot was generated...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27909300/cyanobacterial-photoprotection-by-the-orange-carotenoid-protein
#15
REVIEW
Diana Kirilovsky, Cheryl A Kerfeld
In photosynthetic organisms, the production of dangerous oxygen species is stimulated under high irradiance. To cope with this stress, these organisms have evolved photoprotective mechanisms. One type of mechanism functions to decrease the energy arriving at the photochemical centres by increasing thermal dissipation at the level of antennae. In cyanobacteria, the trigger for this mechanism is the photoactivation of a soluble carotenoid protein, the orange carotenoid protein (OCP), which is a structurally and functionally modular protein...
December 2, 2016: Nature Plants
https://www.readbyqxmd.com/read/27909291/engineering-of-a-thermostable-esterase-est816-to-improve-its-quorum-quenching-activity-and-the-underlying-structural-basis
#16
Xiwen Liu, Li-Chuang Cao, Xin-Jiong Fan, Yu-Huan Liu, Wei Xie
N-acyl-homoserine lactones (AHLs) are small diffusible molecules called autoinducers that mediate cell-to-cell communications. Enzymatic degradation of AHLs is a promising bio-control strategy known as quorum-quenching. To improve the quorum-quenching activity of a thermostable esterase Est816, which had been previously cloned, we have engineered the enzyme by random mutagenesis. One of the mutants M2 with double amino acid substitutions (A216V/K238N) showed 3-fold improvement on catalytic efficiency. Based on the crystal structure determined at 2...
December 2, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27908716/self-healing-gelatin-ionogels
#17
REVIEW
Anshu Sharma, Kamla Rawat, Pratima R Solanki, H B Bohidar
We demonstrate room temperature (20°C) self-healing, and substantial recovery (68-96%) of gel rigidity of gelatin, a polypeptide, ionogels (made in 1-ethyl-3-methylimidazolium chloride ionic liquid (IL) solutions via thermal treatment, IL≤5% (w/v)) after they were cut using a surgical blade. The recovery process did not require any stimuli, and the complete healing under ambient condition required about 10h.The self-healing owed its origin to the reformation of network structures via imidazolium ion mediated charge quenching of deprotonated residues, and hydrophobic interaction between neighbouring alkyl tails of IL molecules...
November 28, 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27908712/potential-of-lignin-from-canna-edulis-ker-residue-in-the-inhibition-of-%C3%AE-d-glucosidase-kinetics-and-interaction-mechanism-merging-with-docking-simulation
#18
Fan Xie, Shengxiang Gong, Wei Zhang, Jinhong Wu, Zhengwu Wang
In this study, we extracted lignin from Canna edulis ker residue. Its chemical structure, inhibitory activity on α-d-glucosidase, and kinetics as well as interaction mechanism were investigated by using spectrum analysis and docking simulation. The isolated lignin was composed by guaiacyl and syringal units, and exhibited stronger inhibition on α-d-glucosidase than acarbose with the half maximal inhibitory concentration at 5.3±0.3μM. It was a non-competitive inhibitior with Km and Ki values of 0.53±0.02mM and 0...
November 28, 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27908242/participation-of-two-carbonic-anhydrases-of-the-alpha-family-in-photosynthetic-reactions-in-arabidopsis-thaliana
#19
E M Zhurikova, L K Ignatova, N N Rudenko, V A Mudrik, D V Vetoshkina, B N Ivanov
The expression of genes of two carbonic anhydrases (CA) belonging to the α-family, α-CA2 and α-CA4 (according to the nomenclature in N. Fabre et al. (2007) Plant Cell Environ., 30, 617-629), was studied in arabidopsis (Arabidopsis thaliana, var. Columbia) leaves. The expression of the At2g28210 gene coding α-CA2 decreased under increase in plant illumination, while the expression of the At4g20990 gene coding α-CA4 increased. Under conditions close to optimal for photosynthesis, in plants with gene At2g28210 knockout, the effective quantum yield of photosystem 2 and the light-induced accumulation of hydrogen peroxide in leaves were lower than in wild type plants, while the coefficient of non-photochemical quenching of leaf chlorophyll a fluorescence and the rate of CO2 assimilation in leaves were higher...
October 2016: Biochemistry. Biokhimii︠a︡
https://www.readbyqxmd.com/read/27908013/oscillation-quenching-in-third-order-phase-locked-loop-coupled-by-mean-field-diffusive-coupling
#20
S Chakraborty, M Dandapathak, B C Sarkar
We explored analytically the oscillation quenching phenomena (amplitude death and parameter dependent inhomogeneous steady state) in a coupled third order phase locked loop (PLL) both in periodic and chaotic mode. The phase locked loops were coupled through mean field diffusive coupling. The lower and upper limits of the quenched state were identified in the parameter space of the coupled PLL using the Routh-Hurwitz technique. We further observed that the ability of convergence to the quenched state of coupled PLLs depends on the design parameters...
November 2016: Chaos
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