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1. Fundamental uncertainty equations for nuclear dating applied to the 140Ba-140La and 227Th-223Ra chronometers

Author:
Pommé, S.; Collins, S.M.; Harms, A.; Jerome, S.M.
Source:
Journal of environmental radioactivity 2016 v.162-163 pp. 358-370
ISSN:
0265-931X
Subject:
half life,   etc   ; equations; radionuclides; uncertainty;     Show all 4 Subjects
Abstract:
... Basic equations for age dating through activity ratio measurements are presented and applied to nuclear chronometers based on parent-daughter decay. Uncertainty propagation formulae are derived which relate the relative uncertainty on the half-lives and measured activity ratios with the relative uncertainty on the calculated time of a nuclear event. Particular attention is paid to the case of rela ...
DOI:
10.1016/j.jenvrad.2016.06.013

2. Tissue-specific turnover rates of the nitrogen stable isotope as functions of time and growth in a cyprinid fish

Author:
Busst, Georgina M. A.; Britton, J. Robert
Source:
Hydrobiologia 2018 v.805 no.1 pp. 49-60
ISSN:
0018-8158
Subject:
half life,   etc   ; Barbus barbus; diet; fish; juveniles; muscles; nitrogen; stable isotopes; tissues;     Show all 9 Subjects
Abstract:
... Ecological applications of stable isotope data require knowledge on the isotopic turnover rate of tissues, usually described as the isotopic half-life in days (T ₀.₅) or the change in mass (G ₀.₅). Ecological studies increasingly analyse tissues collected non-destructively, such as fish fin and scales, but there is limited knowledge on their turnover rates. Determining turnover rates in situ is ch ...
DOI:
10.1007/s10750-017-3276-2

3. Arylazoindazole Photoswitches: Facile Synthesis and Functionalization via SNAr Substitution

Author:
Travieso-Puente, Raquel; Budzak, Simon; Chen, Juan; Stacko, Peter; Jastrzebski, Johann T. B. H.; Jacquemin, Denis; Otten, Edwin
Source:
Journal of the American Chemical Society 2017 v.139 no.9 pp. 3328-3331
ISSN:
1520-5126
Subject:
half life,   etc   ; ambient temperature; cis-trans isomers; isomerization;     Show all 4 Subjects
Abstract:
... A straightforward synthetic route to arylazoindazoles via nucleophilic aromatic substitution is presented. Upon deprotonation of the NH group, a C₆F₅-substituted formazan undergoes facile cyclization as a result of intermolecular nucleophilic substitution (SNAr). This new class of azo photoswitches containing an indazole five-membered heterocycle shows photochemical isomerization with high fatigue ...
DOI:
10.1021/jacs.6b12585

4. Why Are Vinyl Cations Sluggish Electrophiles?

Author:
Byrne, Peter A.; Kobayashi, Shinjiro; Würthwein, Ernst-Ulrich; Ammer, Johannes; Mayr, Herbert
Source:
Journal of the American Chemical Society 2017 v.139 no.4 pp. 1499-1511
ISSN:
1520-5126
Subject:
half life,   etc   ; bromides; cations; energy; ethanol; ionization; photolysis; pyrroles; solvents;     Show all 9 Subjects
Abstract:
... The kinetics of the reactions of the vinyl cations 2 [Ph₂CC⁺–(4-MeO–C₆H₄)] and 3 [Me₂CC⁺–(4-MeO–C₆H₄)] (generated by laser flash photolysis) with diverse nucleophiles (e.g., pyrroles, halide ions, and solvents containing variable amounts of water or alcohol) have been determined photometrically. It was found that the reactivity order of the nucleophiles toward these vinyl cations is the same as ...
DOI:
10.1021/jacs.6b10889

5. Controlling the Isomerization Rate of an Azo-BF2 Switch Using Aggregation

Author:
Qian, Hai; Wang, Yu-Ying; Guo, Dong-Sheng; Aprahamian, Ivan
Source:
Journal of the American Chemical Society 2017 v.139 no.3 pp. 1037-1040
ISSN:
1520-5126
Subject:
half life,   etc   ; azo compounds; isomerization; photochemistry; reaction mechanisms; synthesis;     Show all 6 Subjects
Abstract:
... A novel visible-light activated azo-BF₂ switch possessing a phenanthridinyl π-system has been synthesized, and its switching properties have been characterized as a function of concentration. The switch self-aggregates through π–π interactions, and the degree of aggregation modulates the Z → E thermal isomerization rate. This property allows for the active tuning of the thermal relaxation half-lif ...
DOI:
10.1021/jacs.6b10982

6. Tuning Azoheteroarene Photoswitch Performance through Heteroaryl Design

Author:
Calbo, Joaquín; Weston, Claire E.; White, Andrew J. P.; Rzepa, Henry S.; Contreras-García, Julia; Fuchter, Matthew J.
Source:
Journal of the American Chemical Society 2017 v.139 no.3 pp. 1261-1274
ISSN:
1520-5126
Subject:
half life,   etc   ; absorption; cis-trans isomers; heterocyclic compounds; irradiation; isomerization;     Show all 6 Subjects
Abstract:
... Photoswitchable compounds, which can be reversibly switched between two isomers by light, continue to attract significant attention for a wide array of applications. Azoheteroarenes represent a relatively new but understudied type of photoswitch, where one of the aryl rings from the conventional azobenzene class has been replaced with a five-membered heteroaromatic ring. Initial studies have sugge ...
DOI:
10.1021/jacs.6b11626

7. Probing Enhanced Double-Strand Break Formation at Abasic Sites within Clustered Lesions in Nucleosome Core Particles

Author:
Banerjee, Samya; Chakraborty, Supratim; Jacinto, Marco Paolo; Paul, Michael D.; Balster, Morgan V.; Greenberg, Marc M.
Source:
Biochemistry 2017 v.56 no.1 pp. 14-21
ISSN:
1520-4995
Subject:
half life,   etc   ; DNA; buffers; histones; nucleosomes; nucleotides; pH; phosphates;     Show all 8 Subjects
Abstract:
... DNA is rapidly cleaved under mild alkaline conditions at apyrimidinic/apurinic sites, but the half-life is several weeks in phosphate buffer (pH 7.5). However, abasic sites are ∼100-fold more reactive within nucleosome core particles (NCPs). Histone proteins catalyze the strand scission, and at superhelical location 1.5, the histone H4 tail is largely responsible for the accelerated cleavage. The ...
DOI:
10.1021/acs.biochem.6b01144

8. Stability of betanin in pitaya powder and confection as affected by resistant maltodextrin

Author:
Shaaruddin, Safura; Mohd Ghazali, Hasanah; Mirhosseini, Seyed Hamed; Muhammad, Kharidah
Source:
Lebensmittel-Wissenschaft + [i.e. und] Technologie 2017
ISSN:
0023-6438
Subject:
half life,   etc   ; Cactaceae; juices; maltodextrins; spray drying; sugars; temperature;     Show all 7 Subjects
Abstract:
... Physicochemical properties and stability of betanin in pitaya juice spray dried with maltodextrin (MDp) and resistant maltodextrin (RMDp), and its stability after incorporation into sugar confection were assessed. MDp exhibited more favorable powder properties with higher betanin retention, compared to RMDp. Morphology of MDp exhibited well defined spheres as compared to RMDp which displayed agglo ...
DOI:
10.1016/j.lwt.2017.05.031

9. Augmenting atrazine and hexachlorobenzene degradation under different soil redox conditions in a bioelectrochemistry system and an analysis of the relevant microorganisms

Author:
Wang, Hui; Cao, Xian; Li, Lei; Fang, Zhou; Li, Xianning
Source:
Ecotoxicology and environmental safety 2018 v.147 pp. 735-741
ISSN:
0147-6513
Subject:
half life,   etc   ; Desulfitobacterium; Desulfuromonas; Rhodocyclaceae; anodes; atrazine; bioelectrochemistry; hexachlorobenzene; microbial communities; microbial fuel cells; microorganisms; pollutants; soil; sustainable technology;     Show all 14 Subjects
Abstract:
... Soil microbial fuel cells (MFCs) are a sustainable technology that degrades organic pollutants while generating electricity. However, there have been no detailed studies of the mechanisms of pollutant degradation in soil MFCs. In this study, the effects of external resistance and electrode effectiveness on atrazine and hexachlorobenzene (HCB) degradation were evaluated, the performance of soil MFC ...
DOI:
10.1016/j.ecoenv.2017.09.033

10. Reduced graphene oxide enhancing the photoelectrochemical properties of poly(3-hexylthiophene)

Author:
Gonçalves, R.; Moraes, F.C.; Pereira, E.C.
Source:
Carbon 2016 v.109 pp. 57-64
ISSN:
0008-6223
Subject:
half life,   etc   ; carbon; graphene oxide; photocatalysis; polymers;     Show all 5 Subjects
Abstract:
... Poly(3-hexylthiophene) has been used in different photoelectrochemical devices as active material. However, its efficiency regarding photo-conversion is low and the coupling with a second compound is necessary to reduce the electron-hole recombination effect on the generation of photocurrent. The low efficiency could be related to the organization of the polymer. In this work, we propose the use o ...
DOI:
10.1016/j.carbon.2016.07.041

11. Analytical solutions for diffusion of organic contaminant through GCL triple-layer composite liner considering degradation in liner

Author:
Wu, Xun; Shi, Jianyong; He, Jun
Source:
Environmental earth sciences 2016 v.75 no.20 pp. 1371-1371
ISSN:
1866-6280
Subject:
half life,   etc   ; clay; landfills; mass transfer; sorption;     Show all 5 Subjects
Abstract:
... Analytical solutions are presented for analyzing diffusion of organic contaminant through a triple-layer composite liner consisting of a geomembrane, a geosynthetic clay liner (GCL) and an attenuation liner (AL). The degradation of organic contaminant in the GCL and AL is considered. Steady-state and full analytical solutions are obtained for two scenarios with zero-concentration or zero-mass-flux ...
DOI:
10.1007/s12665-016-6145-9

12. Rational Substitution of Surface Acidic Residues for Enhancing the Thermostability of Thermolysin

Author:
Zhu, Fucheng; Zhuang, Yu; Wu, Bin; Li, Jiahuang; He, Bingfang
Source:
Applied biochemistry and biotechnology 2016 v.178 no.4 pp. 725-738
ISSN:
0273-2289
Subject:
half life,   etc   ; mutants; prediction; thermal stability;     Show all 4 Subjects
Abstract:
... Solvent-exposed acidic/amide residue (Asp/Glu or Asn/Gln) exerts great effects on the thermostability of protein; however, experimental attempts appear to be time-consuming, so a more scientific, simple, and effective rational strategy is necessary. In this study, molecular dynamic (MD) simulation was performed to analyze two surface acidic residues (Asp37 and Glu119) of thermolysin (TLN) in media ...
DOI:
10.1007/s12010-015-1905-7

13. Acylhydrazones as Widely Tunable Photoswitches

Author:
van Dijken, Derk Jan; Kovaříček, Petr; Ihrig, Svante P.; Hecht, Stefan
Source:
Journal of the American Chemical Society 2015 v.137 no.47 pp. 14982-14991
ISSN:
1520-5126
Subject:
half life,   etc   ; absorbance; spectral analysis;     Show all 3 Subjects
Abstract:
... Molecular photoswitches have attracted much attention in biological and materials contexts. Despite the fact that existing classes of these highly interesting functional molecules have been heavily investigated and optimized, distinct obstacles and inherent limitations remain. Considerable synthetic efforts and complex structure–property relationships render the development and exploitation of new ...
DOI:
10.1021/jacs.5b09519

14. Air-Persistent Monomeric (Amino)(carboxy) Radicals Derived from Cyclic (Alkyl)(Amino) Carbenes

Author:
Mahoney, Janell K.; Martin, David; Thomas, Fabrice; Moore, Curtis E.; Rheingold, Arnold L.; Bertrand, Guy
Source:
Journal of the American Chemical Society 2015 v.137 no.23 pp. 7519-7525
ISSN:
1520-5126
Subject:
half life,   etc   ; endothermy; free radicals;     Show all 3 Subjects
Abstract:
... A series of monomeric (amino)(carboxy) radicals featuring carbonyl substituents with increasing electron-withdrawing properties (3a, phenyl; 3b, 3,5-bis(trifluoromethyl)phenyl; 3c, perfluorophenyl; 3d, heptafluoropropyl; 3e, 2H-pyrroliumyl) were synthesized in two or three steps from stable cyclic (alky)(amino)carbenes (CAACs). Although (amino)(carboxy) radicals had been previously considered as h ...
DOI:
10.1021/jacs.5b04414

15. Stepwise Two-Photon-Gated Photochemical Reaction in Photochromic [2.2]Paracyclophane-Bridged Bis(imidazole dimer)

Author:
Mutoh, Katsuya; Nakagawa, Yuki; Sakamoto, Akira; Kobayashi, Yoichi; Abe, Jiro
Source:
Journal of the American Chemical Society 2015 v.137 no.17 pp. 5674-5677
ISSN:
1520-5126
Subject:
half life,   etc   ; absorption; irradiation; photons;     Show all 4 Subjects
Abstract:
... Stepwise two-photon processes not only have great potential for efficient light harvesting but also can provide valuable insights into novel photochemical sciences. Here we have designed a [2.2]paracyclophane-bridged bis(imidazole dimer), a molecule that is composed of two photochromic units and absorbs two photons in a stepwise manner. The absorption of the first photon leads to the formation of ...
DOI:
10.1021/jacs.5b02862

16. Evaluating the influence of half-life, milk:plasma partition coefficient, and volume of distribution on lactational exposure to chemicals in children

Author:
Verner, Marc-André; Plouffe, Laurence; Kieskamp, Kyra K.; Rodríguez-Leal, Inés; Marchitti, Satori A.
Source:
Environment international 2017 v.102 pp. 223-229
ISSN:
0160-4120
Subject:
biological half-life; half life,   etc   ; Monte Carlo method; breast milk; children; decision support systems; equations; lactation; regression analysis; simulation models; women;     Show all 11 Subjects
Abstract:
... Women are exposed to multiple environmental chemicals, many of which are known to transfer to breast milk during lactation. However, little is known about the influence of the different chemical-specific pharmacokinetic parameters on children's lactational dose. Our objective was to develop a generic pharmacokinetic model and subsequently quantify the influence of three chemical-specific parameter ...
DOI:
10.1016/j.envint.2017.03.007

17. A novel biodegradation pathway of the endocrine-disruptor di(2-ethyl hexyl) phthalate by Pleurotus ostreatus based on quantum chemical investigation

Author:
Ahuactzin-Pérez, Miriam; Tlecuitl-Beristain, Saúl; García-Dávila, Jorge; Santacruz-Juárez, Ericka; González-Pérez, Manuel; Gutiérrez-Ruíz, María Concepción; Sánchez, Carmen
Source:
Ecotoxicology and environmental safety 2018 v.147 pp. 494-499
ISSN:
0147-6513
Subject:
half life,   etc   ; Pleurotus ostreatus; acetic acid; biodegradation; biomass production; butanediol; carbon; energy; gas chromatography-mass spectrometry; glucose; mammals; oxidation; phthalates; phthalic acid; plasticizers;     Show all 15 Subjects
Abstract:
... Di(2-ethyl hexyl) phthalate (DEHP) is a plasticizer that interfere with endocrine systems in mammals. Growth parameters for Pleurotus ostreatus grown on media containing glucose and different concentrations of DEHP (0, 500 and 1000mg/L) were evaluated. The highest biomass production was observed in medium supplemented with 1000mg of DEHP/L. Half-life of DEHP biodegradation, biodegradation constant ...
DOI:
10.1016/j.ecoenv.2017.09.004

18. Effects of temperature and PEG grafting density on the translocation of PEGylated nanoparticles across asymmetric lipid membrane

Author:
Zhang, Zuoheng; Lin, Xubo; Gu, Ning
Source:
Colloids and Surfaces B: Biointerfaces 2017 v.160 pp. 92-100
ISSN:
0927-7765
Subject:
half life,   etc   ; asymmetric membranes; colloids; eukaryotic cells; lipids; membrane permeability; molecular dynamics; nanoparticles; plasma membrane; temperature;     Show all 10 Subjects
Abstract:
... Plasma membrane internalization of nanoparticles (NPs) is important for their biomedical applications such as drug-delivery carriers. On one hand, in order to improve their half-life in circulation, PEGylation has been widely used. However, it may hinder the NPs’ membrane internalization ability. On the other hand, higher temperature could enhance the membrane permeability and may affect the NPs’ ...
DOI:
10.1016/j.colsurfb.2017.09.013

19. High spatio-temporal-resolution detection of chlorophyll fluorescence dynamics from a single chloroplast with confocal imaging fluorometer

Author:
Tseng, Yi-Chin; Chu, Shi-Wei
Source:
Plant methods 2017 v.13 no.1 pp. 1-43
ISSN:
1746-4811
Subject:
half life,   etc   ; chlorophyll; chloroplasts; fluorescence; image analysis; photosynthesis; plant physiology; temporal variation; valleys;     Show all 9 Subjects
Abstract:
... BACKGROUND: Chlorophyll fluorescence (CF) is a key indicator to study plant physiology or photosynthesis efficiency. Conventionally, CF is characterized by fluorometers, which only allows ensemble measurement through wide-field detection. For imaging fluorometers, the typical spatial and temporal resolutions are on the order of millimeter and second, far from enough to study cellular/sub-cellular ...

20. Visualization of zinc dynamics in intact plants using positron imaging of commercially available 65Zn

Author:
Suzui, Nobuo; Yin, Yong-Gen; Ishii, Satomi; Sekimoto, Hitoshi; Kawachi, Naoki
Source:
Plant methods 2017 v.13 no.1 pp. 1-40
ISSN:
1746-4811
Subject:
half life,   etc   ; Oryza sativa; electrons; image analysis; inflorescences; nutrient transport; rice; zinc;     Show all 8 Subjects
Abstract:
... BACKGROUND: Positron imaging can be used to non-destructively visualize the dynamics of a positron-emitting radionuclide in vivo, and is therefore a tool for understanding the mechanisms of nutrient transport in intact plants. The transport of zinc, which is one of the most important nutrient elements for plants, has so far been visualized by positron imaging using ⁶²Zn (half-life: 9.2 h), which i ...