U.S. flag

An official website of the United States government

PubAg

Main content area

You searched for: Subject "half life" Remove constraint Subject: "half life"
Start Over

Search

9,348  Search Results

« Previous | 1 - 20 of 9,348 |
Number of results to display per page

Search Results

1. Fast T-Type Photochromic Crystals of Diarylbenzene

Author:
Hamatani, Shota; Kitagawa, Daichi; Kobatake, Seiya
Source:
Journal of physical chemistry 2021 v.125 no.8 pp. 4588-4594
ISSN:
1932-7455
Subject:
half life,   etc   ; color; hydrogen; photoirradiation;     Show all 4 Subjects
Abstract:
... Photochromic molecules are of great interest as light-driven molecular switches in research fields of material and life sciences. In particular, fast T-type photochromic molecules with half-life times of the thermal back reaction (t₁/₂) on the order of milliseconds can change not only their color but also their physicochemical properties only under photoirradiation. Herein, we report fast T-type p ...
DOI:
10.1021/acs.jpcc.0c10988

2. Deep sequencing of pre-translational mRNPs reveals hidden flux through evolutionarily conserved alternative splicing nonsense-mediated decay pathways

Author:
Kovalak, Carrie; Donovan, Scott; Bicknell, Alicia A.; Metkar, Mihir; Moore, Melissa J.
Source:
Genome biology 2021 v.22 no.1 pp. 132
ISSN:
1474-760X
Subject:
half life,   etc   ; exons; homeostasis; precipitin tests; prognosis;     Show all 5 Subjects
Abstract:
... BACKGROUND: Alternative splicing, which generates multiple mRNA isoforms from single genes, is crucial for the regulation of eukaryotic gene expression. The flux through competing splicing pathways cannot be determined by traditional RNA-Seq, however, because different mRNA isoforms can have widely differing decay rates. Indeed, some mRNA isoforms with extremely short half-lives, such as those sub ...
DOI:
10.1186/s13059-021-02309-y

3. The Hantzsch reaction for nitrogen-13 PET: preparation of [¹³N]nifedipine and derivatives

Author:
Blower, Julia E.; Ma, Michelle T.; Al-Salemee, Fahad A. I.; Gee, Antony D.
Source:
Chemical communications 2021 v.57 no.40 pp. 4962-4965
ISSN:
1364-548X
Subject:
half life,   etc   ; ammonia; condensation reactions; drugs;     Show all 4 Subjects
Abstract:
... Nitrogen-13 is an attractive but under-used PET radionuclide for labelling molecules of biological and pharmaceutical interest, complementing other PET radionuclides. Its short half-life (t₁/₂ = 9.97 min) imposes synthetic challenges, but we have expanded the hitherto limited pool of ¹³N labelling strategies and tracers by adapting the multicomponent Hantzsch condensation reaction to prepare a lib ...
DOI:
10.1039/d1cc00495f

4. Temporal trends of atmospheric PAHs: Implications for the influence of the clean air action

Author:
Zhu, Fu-Jie; Ma, Wan-Li; Hu, Peng-Tuan; Zhang, Zi-Feng; Li, Yi-Fan
Source:
Journal of cleaner production 2021 v.296 pp. 126494
ISSN:
0959-6526
Subject:
half life,   etc   ; air; regression analysis; China;     Show all 4 Subjects
Abstract:
... A significant decline with primary air pollutants has occurred in China since 2013, benefiting from the Clean Air Action. Polycyclic aromatic hydrocarbons (PAHs), as ubiquitous organic pollutants in atmosphere, could also be influenced by the Action. However, related studies are limited in China. In this study, atmospheric PAHs in Harbin from June 2014 to May 2019 were monitored to evaluate the in ...
DOI:
10.1016/j.jclepro.2021.126494

5. Ethynylhydroxycarbene (H–C≡C–C̈–OH)

Author:
Bernhardt, Bastian; Ruth, Marcel; Eckhardt, André K.; Schreiner, Peter R.
Source:
Journal of the American Chemical Society 2021 v.143 no.10 pp. 3741-3746
ISSN:
1520-5126
Subject:
half life,   etc   ; irradiation; isomers; potential energy; pyrolysis;     Show all 5 Subjects
Abstract:
... The species on the C₃H₂O potential energy surface have long been known to play a vital role in extraterrestrial chemistry. Here we report on the hitherto uncharacterized isomer ethynylhydroxycarbene (H–C≡C–C̈–OH, 1) generated by high-vacuum flash pyrolysis of ethynylglyoxylic acid ethyl ester and trapped in solid argon matrices at 3 and 20 K. Upon irradiation at 436 nm trans-1 rearranges to its hi ...
DOI:
10.1021/jacs.1c00897

6. A novel method based on 220Rn (thoron) exhalation rate of indoor surfaces for robust estimates of 220Rn concentration and equilibrium factor to compute inhalation dose

Author:
Kanse, S.D.; Sahoo, B.K.; Gaware, J.J.; Sapra, B.K.
Source:
Chemosphere 2021 v.267 pp. 128908
ISSN:
0045-6535
Subject:
half life,   etc   ; air; breathing; radon; India;     Show all 5 Subjects
Abstract:
... The research into ²²⁰Rn (thoron) has generated an increasing interest in recent times due to the realisation of its radiological importance in many indoor environments. Though it is assumed that the contribution of ²²⁰Rn, per se, to the inhalation dose is negligible in comparison with that of its decay products, this may not be always true. Correct estimation of inhalation dose due to thoron requi ...
DOI:
10.1016/j.chemosphere.2020.128908

7. Natural attenuation characteristics and comprehensive toxicity changes of C9 aromatics under simulated marine conditions

Author:
Li, Dawei; Wu, Jiangyue; Liu, Jiaqi; Li, Aifeng; Meng, Fanping
Source:
Journal of environmental sciences (China) 2021 v.109 pp. 26-35
ISSN:
1001-0742
Subject:
half life,   etc   ; biodegradation; luminescence; marine environment; seawater; toxicity; China;     Show all 7 Subjects
Abstract:
... Microcosmic experiments were performed under a simulated marine environment to investigate the natural attenuation of C9 aromatics using nine components (propylbenzene, isopropylbenzene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and indene). This research aims to assess the contribution of biodegradation and abiotic acti ...
DOI:
10.1016/j.jes.2021.02.029

8. Fe,N-doped carbon as peroxidase mimics for single-use colorimetric bioassays

Author:
Wang, Lumin; Xue, Jialu; Chang, Jin; Yu, Chenyang; Dai, Henghan; Yao, Zhenjie; Zhou, Jinyuan; Sun, Gengzhi; Huang, Wei
Source:
Journal of materials science 2021 v.56 no.24 pp. 13579-13589
ISSN:
0022-2461
Subject:
half life,   etc   ; biocompatibility; carbon; catalysts; catalytic activity; colorimetry; paper; peroxidase;     Show all 8 Subjects
Abstract:
... Nanozymes as promising alternatives to natural enzymes have attracted enormous attentions for their high robustness, low cost, and tunable activity. Among various candidates, carbonaceous nanomaterials possess extra advantage features of designable surface properties and good biocompatibility. However, their peroxidase-like activity is typically moderate owing to the short half-life of radical hyd ...
DOI:
10.1007/s10853-021-06190-9

9. The paradoxical and still obscure properties of fungal extracellular vesicles

Author:
Piffer, Alicia C.; Kuczera, Diogo; Rodrigues, Marcio L.; Nimrichter, Leonardo
Source:
Molecular immunology 2021 v.135 pp. 137-146
ISSN:
0161-5890
Subject:
half life,   etc   ; fungi; immunization; immunology; nucleic acids; polysaccharides; virulence;     Show all 7 Subjects
Abstract:
... Early compositional studies of fungal EVs revealed a complex combination of biomolecules, including proteins, lipids, glycans, polysaccharides, nucleic acid and pigments, indicating that these compartments could be involved with multiple functions. Curiously, some of the activities attributed to fungal EVs were already attested experimentally and are implicated with contrasting effects in vitro an ...
DOI:
10.1016/j.molimm.2021.04.009

10. Externally triggered release of growth factors - A tissue regeneration approach

Author:
Cheah, Ernest; Wu, Zimei; Thakur, Sachin S.; O'Carroll, Simon J.; Svirskis, Darren
Source:
Journal of controlled release 2021 v.332 pp. 74-95
ISSN:
0168-3659
Subject:
half life,   etc   ; biocompatible materials; temperature; therapeutics; tissue repair; ultrasonics;     Show all 6 Subjects
Abstract:
... Tissue regeneration aims to achieve functional restoration following injury by creating an environment to enable the body to self-repair. Strategies for regeneration rely on the introduction of biomaterial scaffolding, cells and bioactive molecules into the body, at or near the injury site. Of these bioactive molecules, growth factors (GFs) play a pivotal role in directing regenerative pathways fo ...
DOI:
10.1016/j.jconrel.2021.02.015

11. Polyglycerol for Half-Life Extension of Proteins—Alternative to PEGylation?

Author:
Tully, Michael; Dimde, Mathias; Weise, Christoph; Pouyan, Paria; Licha, Kai; Schirner, Michael; Haag, Rainer
Source:
Biomacromolecules 2021 v.22 no.4 pp. 1406-1416
ISSN:
1526-4602
Subject:
half life,   etc   ; chemical bonding; hydrodynamics; interleukin-1; pharmacokinetics; therapeutics;     Show all 6 Subjects
Abstract:
... Since several decades, PEGylation is known to be the clinical standard to enhance pharmacokinetics of biotherapeutics. In this study, we introduce polyglycerol (PG) of different lengths and architectures (linear and hyperbranched) as an alternative polymer platform to poly(ethylene glycol) (PEG) for half-life extension (HLE). We designed site-selective N-terminally modified PG-protein conjugates o ...
DOI:
10.1021/acs.biomac.0c01627

12. Enhanced metabolic bioavailability of tetrahydrocurcumin after oral supplementation of a γ-cyclodextrin curcumin complex

Author:
Hundshammer, Christian; Schön, Christiane; Kimura, Madoka; Furune, Takahiro; Terao, Keiji; Elgeti, Dana; Mohr, Rachela
Source:
Journal of functional foods 2021 v.79 pp. 104410
ISSN:
1756-4646
Subject:
half life,   etc   ; bioavailability; blood serum; curcumin; cyclodextrins; metabolites;     Show all 6 Subjects
Abstract:
... Tetrahydrocurcumin, curcumin’s main metabolite, exhibits properties similar to curcumin with superior effectiveness in certain categories. However, as curcumin’s bioavailabilty and in vivo conversion are low, formulations yielding appreciable tetrahydrocurcumin concentrations are required to convey potential health benefits either through tetrahydrocurucmin itself, complementary or synergistic to ...
DOI:
10.1016/j.jff.2021.104410

13. An Open-shell, Luminescent, Two-Dimensional Coordination Polymer with a Honeycomb Lattice and Triangular Organic Radical

Author:
Kimura, Shun; Uejima, Motoyuki; Ota, Wataru; Sato, Tohru; Kusaka, Shinpei; Matsuda, Ryotaro; Nishihara, Hiroshi; Kusamoto, Tetsuro
Source:
Journal of the American Chemical Society 2021 v.143 no.11 pp. 4329-4338
ISSN:
1520-5126
Subject:
half life,   etc   ; coordination polymers; crystal structure; luminescence; photoirradiation; photostability; topology;     Show all 7 Subjects
Abstract:
... The use of organic radicals as building blocks is an effective approach to the production of open-shell coordination polymers (CPs). Two-dimensional (2D) CPs with honeycomb spin–lattices have attracted attention because of the unique electronic structures and physical properties afforded by their structural topology. However, radical-based CPs with honeycomb spin–lattices tend to have low chemical ...
DOI:
10.1021/jacs.0c13310

14. Kinetics of Thiocyanate Formation by Reaction of Cyanide with Tetrathionate

Author:
Kurashova, Irina; Kamyshny, Alexey, Jr.
Source:
Aquatic geochemistry 2021 v.27 no.1 pp. 63-77
ISSN:
1380-6165
Subject:
half life,   etc   ; activation energy; geochemistry; hydrogen cyanide; pH; thiocyanates;     Show all 6 Subjects
Abstract:
... In aquatic systems a reaction between tetrathionate and cyanide results in the formation of thiocyanate. We have studied kinetics of the reactions of tetrathionate with free cyanide and two cyanide complexes, hexacyanoferrate(II) and hexacyanoferrate(III), at the environmentally relevant conditions. For the reaction between tetrathionate and free cyanide, the rate constant and the activation energ ...
DOI:
10.1007/s10498-020-09385-9

15. Magnitude and decline of pesticide co‐formulant residues in vegetables and fruits: results from field trials compared to estimated values

Author:
Balmer, Marianne E; Janser, Daniel; Schaller, Ulrich; Krauss, Jürgen; Geiser, H Christoph; Poiger, Thomas
Source:
Pest management science 2021 v.77 no.3 pp. 1187-1196
ISSN:
1526-498X
Subject:
half life,   etc   ; celery; parsley; pesticides; plant protection; prediction; solvents; volatilization;     Show all 8 Subjects
Abstract:
... BACKGROUND: The application of plant protection products (PPPs) leads to the formation of residues in treated crops. Even though PPPs contain considerable amounts of co‐formulants, regulation and monitoring of residues normally focus on the active substances (a.s.) only. For our study we selected four commonly used co‐formulants (three anionic surfactants and one organic solvent) and investigated ...
DOI:
10.1002/ps.6128

16. The Effects of Stably Tethered BMP-2 on MC3T3-E1 Preosteoblasts Encapsulated in a PEG Hydrogel

Author:
Schoonraad, Sarah A.; Trombold, Michael L.; Bryant, Stephanie J.
Source:
Biomacromolecules 2021 v.22 no.3 pp. 1065-1079
ISSN:
1526-4602
Subject:
half life,   etc   ; bone formation; bone morphogenetic proteins; dexamethasone; hydrogels; metalloproteinases;     Show all 6 Subjects
Abstract:
... Bone morphogenetic protein-2 (BMP-2) is a clinically used osteoinductive growth factor. With a short half-life and side effects, alternative delivery approaches are needed. This work examines thiolation of BMP-2 for chemical attachment to a poly(ethylene glycol) hydrogel using thiol-norbornene click chemistry. BMP-2 retained bioactivity post-thiolation and was successfully tethered into the hydrog ...
DOI:
10.1021/acs.biomac.0c01085

17. Microbial degradation of hydrophobic emerging contaminants from marine sediment slurries (Capbreton Canyon) to pure bacterial strain

Author:
Azaroff, Alyssa; Monperrus, Mathilde; Miossec, Carole; Gassie, Claire; Guyoneaud, Rémy
Source:
Journal of hazardous materials 2021 v.402 pp. 123477
ISSN:
0304-3894
Subject:
half life,   etc   ; biodegradation; hydrophobicity; marine environment; marine sediments; remediation; slurries;     Show all 7 Subjects
Abstract:
... Despite emerging contaminants (ECs) are more and more monitored in environmental matrices, there is still a lack of data in marine ecosystems, especially on their fate and degradation potentials. In this work, for the first time, the degradation potential of synthetic musks (galaxolide and tonalide), UV filters (padimate O and octocrylene) and a pharmaceutical compound (carbamazepine) was studied ...
DOI:
10.1016/j.jhazmat.2020.123477

18. Cross-coupling of [¹¹C]methyllithium for ¹¹C-labelled PET tracer synthesis

Author:
Helbert, Hugo; Antunes, Ines Farinha; Luurtsema, Gert; Szymanski, Wiktor; Feringa, Ben L.; Elsinga, Philip H.
Source:
Chemical communications 2021 v.57 no.2 pp. 203-206
ISSN:
1364-548X
Subject:
half life,   etc   ; automation; cross-coupling reactions; positron-emission tomography; radiolabeling;     Show all 5 Subjects
Abstract:
... The cross-coupling of aryl bromides with [¹¹C]CH₃Li for the labelling of a variety of tracers for positron emission tomography (PET) is presented. The radiolabelled products were obtained in excellent yields, at rt and after short reaction times (3–5 min) compatible with the half-life of ¹¹C (20.4 min). The automation of the protocol on a synthesis module is investigated, representing an important ...
DOI:
10.1039/d0cc05392a

19. Ecological half-life of radiocesium in white-tailed deer on the Department of Energy's Savannah River Site: What can a half century of field monitoring tell us?

Author:
Gaines, Karen F.; Novak, Peter M.; Novak, James M.
Source:
Journal of environmental radioactivity 2021 v.235-236 pp. 106654
ISSN:
0265-931X
Subject:
biological half-life; half life,   etc   ; Odocoileus virginianus; adults; cesium radioisotopes; data collection; deer; depuration; habitat preferences; herds; isotopes; models; radioactivity; sample size; temporal variation; yearlings; Savannah River Site;     Show all 17 Subjects
Abstract:
... This paper estimates the ¹³⁷Cs ecological half-life of white-tailed deer inhabiting the Department of Energy's Savannah River Site (SRS) based on sex and age using data collected over a 51-year time-period. With a physical half-life of 30.2 yr, the biological half-life for the deer herd is considerably shorter because of the isotope's biochemical mimicry of K+ inside the body. Leveraging this long ...
DOI:
10.1016/j.jenvrad.2021.106654

20. Does the natural carcinogen ptaquiloside degrade readily in groundwater?

Author:
Wu, Jane S.; Clauson-Kaas, Frederik; Lindqvist, Dan Nybro; Rasmussen, Lars Holm; Strobel, Bjarne W.; Hansen, Hans Christian Bruun
Source:
Environmental sciences Europe 2021 v.33 no.1 pp. 24
ISSN:
2190-4707
Subject:
half life,   etc   ; carcinogens; groundwater; hydrolysis; mathematical models; pH; ptaquiloside; soil; temperature; Europe;     Show all 10 Subjects
Abstract:
... BACKGROUND: Ptaquiloside (PTA) is a natural carcinogen found in bracken ferns. PTA is released from the plants via soil to surface and groundwaters from where humans can be exposed via drinking water. Primary degradation of PTA is due to hydrolysis with formation of pterosin B (PTB). Temperature and pH determine the rate of hydrolysis under pure experimental conditions. To assess the applicability ...
DOI:
10.1186/s12302-021-00468-0