Database : MEDLINE
Search on : light [Words]
References found : 731293 [refine]
Displaying: 1 .. 10   in format [Detailed]

page 1 of 73130 go to page                         

  1 / 731293 MEDLINE  
              next record last record
select
to print
Photocopy
Full text

[PMID]: 29524923
[Au] Autor:Zhang Y; Gu AZ; Cen T; Li X; Li D; Chen J
[Ad] Address:Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
[Ti] Title:Petrol and diesel exhaust particles accelerate the horizontal transfer of plasmid-mediated antimicrobial resistance genes.
[So] Source:Environ Int;114:280-287, 2018 Mar 07.
[Is] ISSN:1873-6750
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:Particles exhausted from petrol and diesel consumptions are major components of urban air pollution that can be exposed to human via direct inhalation or other routes due to atmospheric deposition into water and soil. Antimicrobial resistance is one of the most serious threats to modern health care. However, how the petrol and diesel exhaust particles affect the development and spread of antimicrobial resistance genes (ARGs) in various environments remain largely unknown. This study investigated the effects and potential mechanisms of four representative petrol and diesel exhaust particles, namely 97 octane petrol, 93 octane petrol, light diesel oil, and marine heavy diesel oil, on the horizontal transfer of ARGs between two opportunistic Escherichia coli (E. coli) strains, E. coli S17-1 (donor) and E. coli K12 (recipient). The results demonstrated that these four representative types of nano-scale particles induced concentration-dependent increases in conjugative transfer rates compared with the controls. The underlying mechanisms involved in the accelerated transfer of ARGs were also identified, including the generation of intracellular reactive oxygen species (ROS) and the consequent induction of oxidative stress, SOS response, changes in cell morphology, and the altered mRNA expression of membrane protein genes and those involved in the promotion of conjugative transfer. The findings provide new evidences and mechanistic insights into the antimicrobial resistance risks posed by petrol and diesel exhaust particles, and highlight the implications and need for stringent strategies on alternative fuels to mitigate air pollution and health risks.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  2 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Teixeira, Luis Augusto
Full text

[PMID]: 29524852
[Au] Autor:Martinelli AR; Coelho DB; Teixeira LA
[Ad] Address:Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, SP, Brazil.
[Ti] Title:Light touch leads to increased stability in quiet and perturbed balance: Equivalent effects between post-stroke and healthy older individuals.
[So] Source:Hum Mov Sci;58:268-278, 2018 Mar 07.
[Is] ISSN:1872-7646
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:Cerebral damage provoked by stroke may lead to deficits of quiet balance control and of the recovery of body equilibrium following an unanticipated postural perturbation. In this investigation we aimed to evaluate the effect of light touch (LT) of an earth-fixed surface on balance stability in individuals with post-stroke hemiparesis, taking performance of age-matched healthy participants as reference. Evaluations were made in conditions of full and no visual information. Analysis of quiet balance showed that LT induced higher balance stability, with reduced amplitude and velocity of postural sway. Evaluation of the effect of LT on automatic postural responses was made in the task of recovering body equilibrium following a mechanical perturbation of balance leading to fast forward body sway. Results showed that LT led to reduced amplitude of center of mass displacement following the perturbation, in addition to reduced amplitude and velocity of center of pressure under the feet, and lower activation of the lower legs muscles. Those effects of LT were observed in both the post-stroke and control groups, and did not interact with vision availability. Our results indicated then that individuals who suffered a cerebral stroke can stabilize perturbed and non-perturbed postural responses by lightly touching a stable surface to a similar extent of healthy older individuals.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  3 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524850
[Au] Autor:Chouchane K; Pignot-Paintrand I; Bruckert F; Weidenhaupt M
[Ad] Address:Univ. Grenoble Alpes, CNRS, Grenoble INP, Institute of Engineering Univ. Grenoble Alpes, LMGP, F-38000 Grenoble, France.
[Ti] Title:Visible light-induced insulin aggregation on surfaces via photoexcitation of bound thioflavin T.
[So] Source:J Photochem Photobiol B;181:89-97, 2018 Mar 06.
[Is] ISSN:1873-2682
[Cp] Country of publication:Switzerland
[La] Language:eng
[Ab] Abstract:Insulin is known to form amyloid aggregates when agitated in a hydrophobic container. Amyloid aggregation is routinely measured by the fluorescence of the conformational dye thioflavin T, which, when incorporated into amyloid fibers, fluoresces at 480 nm. The kinetics of amyloid aggregation in general is characterized by an initial lag-phase, during which aggregative nuclei form on the hydrophobic surface. These nuclei then lead to the formation of fibrils presenting a rapid growth during the elongation phase. Here we describe a novel mechanism of insulin amyloid aggregation which is surprisingly devoid of a lag-time for nucleation. The excitation of thioflavin T by visible light at 440 nm induces the aggregation of thioflavin T-positive insulin fibrils on hydrophobic surfaces in the presence of strong agitation and at physiological pH. This process is material surface-induced and depends on the fact that surface-adsorbed insulin can bind thioflavin T. Light-induced insulin aggregation kinetics is thioflavin T-mediated and is based on an energy transfer from visible light to the protein via thioflavin T. It relies on a constant supply of thioflavin T and insulin from the solution to the aggregate. The growth rate increases with the irradiance and with the concentration of thioflavin T. The supply of insulin seems to be the limiting factor of aggregate growth. This light-induced aggregation process allows the formation of local surface-bound aggregation patterns.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  4 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524849
[Au] Autor:Di Martino A; Trusova ME; Postnikov PS; Sedlarik V
[Ad] Address:Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Tr.Tomas Bati, 5678, 76001, Zlin, Czech Republic; Research School in Chemistry & Applied Biomedical Sciences, Tomsk Polytechnic University, Lenin Av. 30, 634050 Tomsk, Russian Federation. Electronic address: dimartin
[Ti] Title:Branched poly (lactic acid) microparticles for enhancing the 5-aminolevulinic acid phototoxicity.
[So] Source:J Photochem Photobiol B;181:80-88, 2018 Mar 03.
[Is] ISSN:1873-2682
[Cp] Country of publication:Switzerland
[La] Language:eng
[Ab] Abstract:An innovative microcarrier based on a carboxy-enriched and branched polylactic acid derivative was developed to enhance the in vitro phototoxicity of the photosensitizer and prodrug 5-aminolevulinic. Microparticles, prepared by double emulsion technique and loaded with the prodrug were carefully characterized and the effect of the polymer structure on the chemical, physical and biological properties of the final product was evaluated. Results showed that microparticles have a spherical shape and ability to allocate up to 30 µg of the photosensitizer per mg of carrier despite their difference in solubility. Release studies performed in various simulated physiological conditions demonstrate the influence of the branched structure and the presence of the additional carboxylic groups on the release rate and the possibility to modulate it. In vitro assays conducted on human epithelial adenocarcinoma cells proved the not cytotoxicity of the carriers in a wide range of concentrations. The hemocompatibility and surface proteins adsorption were evaluated at different microparticles concentrations to evaluate the safety and estimate the possible microparticles residential time in the bloodstream. The advantages, of loading 5-aminolevulinic acid in the prepared carrier has been deeply described in terms of enhanced phototoxicity, compared to the free 5-aminolevulinic acid formulation after irradiation with light at 635 nm. The obtained results demonstrate the advantages of the prepared derivative compared to the linear polylactide for future application in photodynamic therapy based on the photosensitizer 5-aminolevulinic acid.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  5 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524823
[Au] Autor:Wang X; Yao J; Wang S; Pan X; Xiao R; Huang Q; Wang Z; Qu R
[Ad] Address:State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
[Ti] Title:Phototransformation of estrogens mediated by Mn(III), not by reactive oxygen species, in the presence of humic acids.
[So] Source:Chemosphere;201:224-233, 2018 Mar 02.
[Is] ISSN:1879-1298
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:Photodegradation of pollutants is classically explained by reaction with reactive oxygen species. However Mn(III) may also remove pollutants, but direct evidence is actually lacking. Here we investigated the role of soluble Mn(III) on phototransformation of four typical estrogens, namely estrone (E1), 17ß-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2), in the presence of Mn(II) and humic acid. Conversion rates of 60.2%, 89.0%, 87.6%, and 80.2% were achieved for E1, E2, E3, and EE2, respectively, after 72 h visible light irradiation. A detailed quenching experiments revealed that soluble Mn(III), and not reactive oxygen species, was the oxidant responsible for estrogen removal. The determination of Mn(III) concentration provided direct proof of the role of Mn(III)-based oxidizers in the conversion of estrogens. Soluble Mn(III) can form complexes with humic acid, and about 6.51 µM of Mn(III)-humic acid was formed from 20 µM of Mn(II) in the presence of 5 mg/L of humic acid. Furthermore, product identification and theoretical computation demonstrated that estrogens are mainly converted into oligomers (dimers, trimers, tetramers, etc.) via a single-electron process. According to these results, the oxidation of Mn(II) to Mn(III) is initiated by superoxide ion (O ) generated from dissolved oxygen in the presence of humic acid under visible light irradiation. The formed soluble Mn(III) strips the estrogens of a single electron to generate phenoxyl radicals, which undergo oligomerization, while leads to regeneration of Mn(II). Hence, the photochemical Mn(II)-Mn(III) redox cycling may significantly influence the fate and transformation of estrogens in waters.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  6 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524820
[Au] Autor:Liu G; Zhou Y; Teng J; Zhang J; You S
[Ad] Address:State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
[Ti] Title:Visible-light-driven photocatalytic activation of peroxymonosulfate by Cu (OH)PO for effective decontamination.
[So] Source:Chemosphere;201:197-205, 2018 Mar 02.
[Is] ISSN:1879-1298
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:The advanced oxidation process (AOP) based on SO radicals draws an increasing interest in water and wastewater treatment. Producing SO radicals from the activation of peroxymonosulfate (PMS) by transition metal ions or oxides may be problematic due to high operational cost and potential secondary pollution caused by metal leaching. To address this challenge, the present study reports the efficient production of SO radicals through visible-light-driven photocatalytic activation (VL-PCA) of PMS by using Cu (OH)PO single crystal for enhanced degradation of a typical recalcitrant organic pollutant, i.e., 2,4-dichlorophenol (2,4-DCP). It took only 7 min to achieve almost 100% removal of 2,4-DCP in the Cu (OH)PO /PMS system under visible-light irradiation and pH-neutral condition. The 2,4-DCP degradation was positively correlated to the amount of Cu (OH)PO and PMS. Both OH and SO radicals were responsible for enhanced degradation performance, indicated by radical scavenger experiments and electron spin resonance (ESR) measurements. The Cu (OH)PO single crystal exhibited good cyclic stability and negligible metal leaching. According to density functional theory (DFT) calculations, the visible-light-driven transformation of two copper states between trigonal bipyramidal sites and octahedral sites in the crystal structure of Cu (OH)PO facilitates the generation of OH and SO radicals from the activation of PMS and cleavage of O-O bonds. This study provides the proof-in-concept demonstration of activation of PMS driven by visible light, making the SO radicals-based AOPs much easier, more economical and more sustainable in engineering applications for water and wastewater treatment.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  7 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524818
[Au] Autor:Souza DM; Reichert JF; Martins AF
[Ad] Address:Chemistry Department, Federal University of Santa Maria, RS, Brazil.
[Ti] Title:A simultaneous determination of anti-cancer drugs in hospital effluent by DLLME HPLC-FLD, together with a risk assessment.
[So] Source:Chemosphere;201:178-188, 2018 Feb 28.
[Is] ISSN:1879-1298
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:Currently, there is an increasing use of anti-cancer drugs, and hence their occurrence in the environment must be properly managed, in particular, in the light of their high degree of toxicity. In this study, analytical methods using HPLC-FLD assisted by microextraction and solid phase extraction, were developed and validated for the determination of doxorubicin, daunorubicin, epirubicin and irinotecan in hospital effluent. The validation results show determination coefficients (r ) higher than 0.99 and recovery values between 74% and 105%, with an intraday precision of <15%.The limit of quantification was 1.0 µg L and there were almost no matrix effects. The methods proposed were employed for the determination of the named chemotherapeutics in effluent samples of the University Hospital of Santa Maria, Brazil and quantified in the range of ≥LOQ ̶ 6.22 µg L . A preliminary ecotoxicological risk assessment showed values that were potentially very harmful, and thus, the treatment of the hospital effluents requires special attention.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  8 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524778
[Au] Autor:Fiaz M; Martínez LC; Costa MDS; Cossolin JFS; Plata-Rueda A; Gonçalves WG; Sant'Ana AEG; Zanuncio JC; Serrão JE
[Ad] Address:Department of Entomology, Federal University of Viçosa, 36570-000 Viçosa, MG, Brazil. Electronic address: fiaz.jahania@gmail.com.
[Ti] Title:Squamocin induce histological and ultrastructural changes in the midgut cells of Anticarsia gemmatalis (Lepidoptera: Noctuidae).
[So] Source:Ecotoxicol Environ Saf;156:1-8, 2018 Mar 07.
[Is] ISSN:1090-2414
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:Annonaceous acetogenins (Annona squamosa Linnaeus) comprises of a series of natural products which are extracted from Annonaceae species, squamocin proved to be highly efficient among those agents. Squamocin is mostly referred as a lethal agent for midgut cells of different insects, with toxic effects when tested against larva of some insects. In present study, LC and LC of squamocin for A. gemmatalis Hübner (Lepidoptera: Noctuidae) were calculated using probit analysis. Morphological changes in midgut cells were analyzed under light, fluorescence and transmission electron microscopes when larvae were treated with LC and LC of squamocin for 24, 48 and 72 h. Results revealed that the maximum damage to midgut cells was found under LC where it showed digestive cells with enlarged basal labyrinth, highly vacuolated cytoplasm, damaged apical surface, cell protrusions to the gut lumen, autophagy and cell death. The midgut goblet cells showed a strong disorganization of their microvilli. Likewise, in insects treated with squamocin, mitochondria were not marked with Mitotracker fluorescent probe, suggesting some molecular damage in these organelles, which was reinforced by decrease in the respiration rate in these insects. These results demonstrate that squamocin has potential to induce enough morphological changes in midgut through epithelial cell damage in A. gemmatalis.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  9 / 731293 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524757
[Au] Autor:Wittmann JJ; Can TV; Eckardt M; Harneit W; Griffin RG; Corzilius B
[Ad] Address:Institute for Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt am Main, Germany.
[Ti] Title:High-precision measurement of the electron spin g factor of trapped atomic nitrogen in the endohedral fullerene N@C .
[So] Source:J Magn Reson;290:12-17, 2018 Mar 06.
[Is] ISSN:1096-0856
[Cp] Country of publication:United States
[La] Language:eng
[Ab] Abstract:The electronic g factor carries highly useful information about the electronic structure of a paramagnetic species, such as spin-orbit coupling and dia- or paramagnetic (de-)shielding due to local fields of surrounding electron pairs. However, in many cases, a near "spin-only" case is observed, in particular for light elements, necessitating accurate and precise measurement of the g factors. Such measurement is typically impeded by a "chicken and egg situation": internal or external reference standards are used for relative comparison of electron paramagnetic resonance (EPR) Larmor frequencies. However, the g factor of the standard itself usually is subject to a significant uncertainty which directly limits the precision and/or accuracy of the sought after sample g factor. Here, we apply an EPR reference-free approach for determining the g factor of atomic nitrogen trapped within the endohedral fullerene C :N@C in its polycrystalline state by measuring the H NMR resonance frequency of dispersing toluene at room temperature. We found a value of g=2.00204(4) with a finally reached relative precision of ∼20 ppm. This accurate measurement allows us to directly compare the electronic properties of N@C to those found in atomic nitrogen in the gas phase or trapped in other solid matrices at liquid helium temperature. We conclude that spin-orbit coupling in N@C at room temperature is very similar in magnitude and of same sign as found in other inert solid matrices and that interactions between the quartet spin system and the C molecular orbitals are thus negligible.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  10 / 731293 MEDLINE  
              first record previous record
select
to print
Photocopy
Full text

[PMID]: 29524753
[Au] Autor:Venkataramanan NS; Suvitha A
[Ad] Address:Department of Chemistry, School of Chemical and Biotechnology (SCBT), SASTRA Deemed University, Thanjavur, 613 401, India. Electronic address: nsvenkataramanan@gmail.com.
[Ti] Title:Nature of bonding and cooperativity in linear DMSO clusters: A DFT, AIM and NCI analysis.
[So] Source:J Mol Graph Model;81:50-59, 2018 Mar 02.
[Is] ISSN:1873-4243
[Cp] Country of publication:United States
[La] Language:eng
[Ab] Abstract:This study aims to cast light on the nature of interactions and cooperativity that exists in linear dimethyl sulfoxide (DMSO) clusters using dispersion corrected density functional theory. In the linear DMSO, DMSO molecules in the middle of the clusters are bound strongly than at the terminal. The plot of the total binding energy of the clusters vs the cluster size and mean polarizabilities vs cluster size shows an excellent linearity demonstrating the presence of cooperativity effect. The computed incremental binding energy of the clusters remains nearly constant, implying that DMSO addition at the terminal site can happen to form an infinite chain. In the linear clusters, two σ-hole at the terminal DMSO molecules were found and the value on it was found to increase with the increase in cluster size. The quantum theory of atoms in molecules topography shows the existence of hydrogen and SO⋯S type in linear tetramer and larger clusters. In the dimer and trimer SO⋯OS type of interaction exists. In 2D non-covalent interactions plot, additional peaks in the regions which contribute to the stabilization of the clusters were observed and it splits in the trimer and intensifies in the larger clusters. In the trimer and larger clusters in addition to the blue patches due to hydrogen bonds, additional, light blue patches were seen between the hydrogen atom of the methyl groups and the sulphur atom of the nearby DMSO molecule. Thus, in addition to the strong H-bonds, strong electrostatic interactions between the sulphur atom and methyl hydrogens exists in the linear clusters.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher


page 1 of 73130 go to page                         
   


Refine the search
  Database : MEDLINE Advanced form   

    Search in field  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/PAHO/WHO - Latin American and Caribbean Center on Health Sciences Information