scholarly journals Reduction of Tetrachloroaurate(III) Ions With Bioligands: Role of the Thiol and Amine Functional Groups on the Structure and Optical Features of Gold Nanohybrid Systems

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1229 ◽  
Author(s):  
Ungor ◽  
Dékány ◽  
Csapó
Keyword(s):  
Amino Acids ◽  
Metal Ion ◽  
Periodic Structures ◽  
Dominant Role ◽  
Molar Ratio ◽  
Experimental Conditions ◽  
Au Nps ◽  
Spontaneous Interaction ◽  
Self Assembled

In this review, the presentation of the synthetic routes of plasmonic gold nanoparticles (Au NPs), fluorescent gold nanoclusters (Au NCs), as well as self-assembled Au-containing thiolated coordination polymers (Au CPs) was highlighted. We exclusively emphasize the gold products that are synthesized by the spontaneous interaction of tetrachloroaurate(III) ions (AuCl4¯) with bioligands using amine and thiolate derivatives, including mainly amino acids. The dominant role of the nature of the applied reducing molecules as well as the experimental conditions (concentration of the precursor metal ion, molar ratio of the AuCl4¯ ions and biomolecules; pH, temperature, etc.) of the syntheses on the size and structure-dependent optical properties of these gold nanohybrid materials have been summarized. While using the same reducing and stabilizing biomolecules, the main differences on the preparation conditions of Au NPs, Au NCs, and Au CPs have been interpreted and the reducing capabilities of various amino acids and thiolates have been compared. Moreover, various fabrication routes of thiol-stabilized plasmonic Au NPs, as well as fluorescent Au NCs and self-assembled Au CPs have been presented via the formation of –(Au(I)-SR)n– periodic structures as intermediates.

scholarly journals Dominant role of αIIbβ3 in platelet interactions with cross-linked fibrin fragment D-dimer

2020 ◽  
Vol 4 (13) ◽  
pp. 2939-2949
Author(s):  
Lorena Buitrago ◽  
Hina Zafar ◽  
Yixiao Zhang ◽  
Jihong Li ◽  
Thomas Walz ◽  
...  
Keyword(s):  
Metal Ion ◽  
Dominant Role ◽  
Binding Pocket ◽  
Vital Role ◽  
Clot Retraction ◽  
Proteolytic Fragment ◽  
Activated Platelets ◽  
Hek Cells ◽  
D Dimer

Abstract Although much is known about the interaction of fibrinogen with αIIbβ3, much less is known about the interaction of platelets with cross-linked fibrin. Fibrinogen residue Lys406 plays a vital role in the interaction of fibrinogen with αIIbβ3, but because it participates in fibrin cross-linking, it is not available for interacting with αIIbβ3. We studied the adhesion of platelets and HEK cells expressing normal and constitutively active αIIbβ3 to both immobilized fibrinogen and D-dimer, a proteolytic fragment of cross-linked fibrin, as well as platelet-mediated clot retraction. Nonactivated platelets and HEK cells expressing normal αIIbβ3 adhered to fibrinogen but not D-dimer, whereas activated platelets as well as HEK cells expressing activated αIIbβ3 both bound to D-dimer. Small-molecule antagonists of the αIIbβ3 RGD (Arg-Gly-Asp) binding pocket inhibited adhesion to D-dimer, and an Asp119Ala mutation that disrupts the β3 metal ion–dependent adhesion site inhibited αIIbβ3-mediated adhesion to D-dimer. D-dimer and a polyclonal antibody against D-dimer inhibited clot retraction. The monoclonal antibody (mAb) 10E5, directed at αIIb and a potent inhibitor of platelet interactions with fibrinogen, did not inhibit the interaction of activated platelets with D-dimer or clot retraction, whereas the mAb 7E3, directed at β3, inhibited both phenomena. We conclude that activated, but not nonactivated, αIIbβ3 mediates interactions between platelets and D-dimer, and by extrapolation, to cross-linked fibrin. Although the interaction of αIIbβ3 with D-dimer differs from that with fibrinogen, it probably involves contributions from regions on β3 that are close to, or that are affected by, changes in the RGD binding pocket.

scholarly journals THE ROLE OF METHIONINE DEFICIENCY IN POLIOVIRUS REPLICATION IN TISSUE CULTURES

1966 ◽  
Vol 123 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Soussan Mohajer ◽  
Janis Gabliks
Keyword(s):  
Amino Acids ◽  
Hela Cells ◽  
Inhibitory Effect ◽  
Monkey Kidney ◽  
Kidney Cells ◽  
Tissue Cultures ◽  
Experimental Conditions ◽  
Methionine Deficiency ◽  
Intracellular Amino Acids

The role of methionine in poliovirus infection in HeLa and monkey kidney cells was investigated by using the methionine analogue l-ethionine. In the presence of 2.0 x 10–3 and 4.0 x 10–3 moles ethionine, the growth of HeLa and monkey kidney cells was significantly inhibited. Under the same experimental conditions, ethionine had no significant effect on the biosynthesis of two strains of poliovirus (Mahoney and Lansing) in HeLa cells, whereas in primary monkey kidney cells, it markedly inhibited the biosynthesis of the Lansing strain of poliovirus. HeLa cells partly depleted of their intracellular amino acids did not change the rate of viral biosynthesis. The inhibitory effect of ethionine on cell growth and viral biosynthesis was reversed by addition of an excess of l-methionine.

scholarly journals Dominant role of the shear strain induced admixture in spin-flip processes in self-assembled quantum dots

2018 ◽  
Vol 97 (24) ◽  
Author(s):  
Adam Mielnik-Pyszczorski ◽  
Krzysztof Gawarecki ◽  
Michał Gawełczyk ◽  
Paweł Machnikowski
Keyword(s):  
Quantum Dots ◽  
Shear Strain ◽  
Dominant Role ◽  
Spin Flip ◽  
Self Assembled

The ORAC (oxygen radical absorbance capacity) index does not reflect the capacity of antioxidants to trap peroxyl radicals

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 39899-39902 ◽  
Author(s):  
E. Dorta ◽  
E. Fuentes-Lemus ◽  
A. Aspée ◽  
E. Atala ◽  
H. Speisky ◽  
...  
Keyword(s):  
Dominant Role ◽  
Kinetic Studies ◽  
Oxygen Radical ◽  
Oxygen Radical Absorbance Capacity ◽  
Peroxyl Radicals ◽  
Experimental Conditions ◽  
Capacity Index

We demonstrate from kinetic studies that under the experimental conditions proposed for the ORAC protocol, ORAC values do not correlate with the capacity of antioxidants to trap peroxyl radicals (ROO˙), suggesting a dominant role of alkoxyl radicals (RO˙) in the assay.

scholarly journals Mechanism of non-enzymic transamination reaction between histidine and α-oxoglutaric acid

1969 ◽  
Vol 112 (5) ◽  
pp. 691-697 ◽  
Author(s):  
V. M. Doctor ◽  
J. Oró
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Metal Ions ◽  
Metal Ion ◽  
Catalytic Effect ◽  
Acid Complex ◽  
Transamination Reaction ◽  
End Products ◽  
Acid Chelate

Non-enzymic transamination reactions at 85° between various amino acids and α-oxoglutaric acid are catalysed by metal ions, e.g. Al3+, Fe2+, Cu2+ and Fe3+. The reaction is optimum at pH4·0. Of the 14 amino acids studied histidine is the most active. In the presence of Al3+ histidine transaminates with α-oxoglutaric acid, forming glutamic acid and Al3+–imidazolylpyruvic acid complex as the end products. However, in the presence of Fe2+ or Cu2+ the products are glutamic acid and a 1:2 metal ion–imidazolylpyruvic acid chelate. The greater effectiveness of histidine in these reactions is attributed to the presence of the tertiary imidazole nitrogen atom, which is involved in the formation of stable sparingly soluble metal ion–imidazolylpyruvic acid complexes or chelates as end products of these reactions. Of the metal ions studied only Al3+, Fe2+, Fe3+ and Cu2+ are effective catalysts for the transamination reactions, and EDTA addition completely inhibits the catalytic effect of the Al3+. Spectrophotometric evidence is presented to demonstrate the presence of metal ion complexes of Schiff bases of histidine as intermediates in the transamination reactions. These results may contribute to understanding the role of histidine in enzyme catalysis.

scholarly journals Dominant role of mitochondria in protection against a delayed neuronal Ca2+ overload induced by endogenous excitatory amino acids following a glutamate pulse

FEBS Letters ◽  
1996 ◽  
Vol 393 (1) ◽  
pp. 135-138 ◽  
Author(s):  
B. Khodorov ◽  
V. Pinelis ◽  
T. Storozhevykh ◽  
O. Vergun ◽  
N. Vinskaya
Keyword(s):  
Amino Acids ◽  
Excitatory Amino Acids ◽  
Dominant Role

scholarly journals Stabilization of metal nanoparticles in highly concentrated colloids

Surface ◽  
2020 ◽  
Vol 12(27) ◽  
pp. 337-345
Author(s):  
Iu. P. Mukha ◽  
◽  
N. V. Vityuk ◽  
A. M. Eremenko ◽  
M. A. Skoryk ◽  
...  
Keyword(s):  
Metal Ion ◽  
Metal Content ◽  
Localized Surface Plasmon ◽  
Molar Ratio ◽  
Colloidal Systems ◽  
Ag Nps ◽  
Experimental Conditions ◽  
Gold And Silver Nanoparticles ◽  
Biological Studies ◽  
Resonance Band

Gold and silver nanoparticles (NPs) have a great potential in nanomedicine. For their use in biological studies there is a need to increase significantly the metal content (active substance) in the dose volume for the injection. Therefore, an urgent task is to find the experimental ways to prevent NPs aggregation in highly concentrated colloidal systems. In this work colloids of Ag NPs, Au NPs and AgAu NPs were prepared in the presence of amino acid as metal ion reducer and particle stabilizer. The polymer pluronic F68 was proposed to increase the stability of NPs and the experimental conditions for the long-term stabilization of colloidal systems with a metal content of 0.4-0.8 mg/ml were developed. It was shown that nanoparticles in all systems maintained nanodimensionality during and after the increasing metal concentration in colloids by 40 times, namely the average size of formed particles was around 10-20 nm. Their optical characteristics remained unchanged, namely, the maxima of the localized surface plasmon resonance band in the absorption spectra had typical position and were placed between 415 and 528 nm depending on molar ratio of metal in nanoparticle.

Site of Lysosome Production During Hepatic Injury

1969 ◽  
Vol 27 ◽  
pp. 348-349
Author(s):  
Nalin J. Unakar
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mouse Liver ◽  
Hepatic Injury ◽  
Close Approximation ◽  
Experimental Conditions ◽  
Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

Chronic Pain: Fundamental Scientific Considerations, Specifically for Legal Claims

2013 ◽  
Vol 18 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Robert J. Barth
Keyword(s):  
Health Outcomes ◽  
Pain Perception ◽  
Driving Forces ◽  
Psychological Treatment ◽  
Dominant Role ◽  
Meta Analysis ◽  
General Medicine ◽  
Pain Syndrome ◽  
Problematic Relationship

Abstract Scientific findings have indicated that psychological and social factors are the driving forces behind most chronic benign pain presentations, especially in a claim context, and are relevant to at least three of the AMA Guides publications: AMA Guides to Evaluation of Disease and Injury Causation, AMA Guides to Work Ability and Return to Work, and AMA Guides to the Evaluation of Permanent Impairment. The author reviews and summarizes studies that have identified the dominant role of financial, psychological, and other non–general medicine factors in patients who report low back pain. For example, one meta-analysis found that compensation results in an increase in pain perception and a reduction in the ability to benefit from medical and psychological treatment. Other studies have found a correlation between the level of compensation and health outcomes (greater compensation is associated with worse outcomes), and legal systems that discourage compensation for pain produce better health outcomes. One study found that, among persons with carpal tunnel syndrome, claimants had worse outcomes than nonclaimants despite receiving more treatment; another examined the problematic relationship between complex regional pain syndrome (CRPS) and compensation and found that cases of CRPS are dominated by legal claims, a disparity that highlights the dominant role of compensation. Workers’ compensation claimants are almost never evaluated for personality disorders or mental illness. The article concludes with recommendations that evaluators can consider in individual cases.

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