China
Africa
Explore chapters and articles related to this topic
Radiochemistry for Preclinical Imaging Studies
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
The main criteria for an optimal chelator/ligand from a radiochemist’s point of view are ease and low cost of precursor synthesis, precursor stability, rapid complexation with 99mTc at ambient temperature, and high complex stability. High complex stability in the formulation solution can be achieved by matching the ligand field strength with the hardness of the metal ion. For example, a soft metal ion and a weak field ligand match well. The reader is referred to the concepts of crystal field theory, ligand field theory, and kinetic stability for further information. One way to increase thermodynamic stability of complexes is to increase the denticity of the ligands, for example, chelate complexes are more stable than monodentate ligands. The higher the number of ligands, the higher the gain in entropy upon complex degradation. With entropy differences dominating the Gibbs free energy, this is synonymous to higher thermodynamic instability with monodentate ligands compared to multidentate chelators.
Uses of eye drops in dermatology, literature review
Published in Journal of Dermatological Treatment, 2022
Sameh Magdy Sarsik, Heba Saed El-Amawy
Bim has been shown to stimulate tyrosinase and increase melanin synthesis (43), additionally, Grimes claimed that the PG F2-α analogue stimulates melanocyte denticity, increases melanocyte size and activity, and increases melanosome transfer to keratinocytes (67). Grimes conducted a 20-week double-blind, placebo-controlled research. Bim alone (n = 11), Bim plus mometasone (n = 10), and mometasone plus placebo (n = 11) were the three treatment groups. After 3 months, both Bim groups had higher response rates than the mometasone plus placebo group, with no differences in side effects or discomfort (67). In small open label research before Grimes, Narung, Jain, and Sing demonstrated the efficacy of Bim in treating refractory focal vitiligo, notably on the face (68).
Clot activators and anticoagulant additives for blood collection. A critical review on behalf of COLABIOCLI WG-PRE-LATAM
Published in Critical Reviews in Clinical Laboratory Sciences, 2021
G. Lima-Oliveira, L. M. Brennan-Bourdon, B. Varela, M. E. Arredondo, E. Aranda, S. Flores, P. Ochoa
EDTA is used mainly in the form of its salts, K2EDTA, K3EDTA, or Na2EDTA. It serves as an anticoagulant by strongly chelating divalent metal ions (calcium and magnesium); it also interacts weakly with transition metal ions such as Fe+++ [22]. Reiter has described the coordination complex formed when ionized calcium and EDTA interact. The coordination center (ionized calcium) is surrounded by an array of bound ions (the ligand EDTA). EDTA binds to calcium via coordinate bonds in which EDTA donates an electron pair to the bond. Ligands can be characterized by their denticity, which is the number of times that a ligand bonds to a metal through noncontiguous donor sites. EDTA is hexadentate and has six lone pairs of electrons available for binding. Four of these pairs belong to carboxyl groups while two belong to the amine groups. Upon complex formation, the hydrogen ions of EDTA, sodium ions of Na2EDTA and potassium ions of K2EDTA or K3EDTA are released and the lone pairs bind calcium (Figure 7) [114].