Explicatia pentru aceasta a fost ca exista anumite contradictii intre prevederile legii adoptate si dificultati de transpunere a acesteia in norme de aplicare si riscul ca de la 1 ianuarie 2016 legea sa nu poata fi aplicata.
'In momentul in care preluat portofoliul, nu se proceda, nu se intampla nimic in directia emiterii normelor de aplicare a Legii 223.
Sheldrick, “SHELXL-97, program for crystal structure refinement,” 1997. 被如下文章引用:. TITLE:. AUTHORS:,.
JOURNAL NAME: DOI: Sep 16, 2014. ABSTRACT: Bisphosphonates are biologically relevant therapeutics for bone disorders and cancer. Reaction of -chlorobutyric acid, phosphorus acid, and phosphorus trichloride without the use of solvent gave the tetrahydrofuranyl-2,2-bisphosphonate sodium salt ( ). The was isolated, characterized in solution by, and NMR spectroscopy and in solid state by single X-Ray crystallography. The crystal structure showed that the forms in the crystal infinite two-dimensional sheets stacked one parallel to the other. A comparison of the chelating properties of with similar hydroxyl bisphosphonate ligands shows that the strength of the Na–O(furanyl/hydroxyl) bond is directly related to the total charge of the ligand anion. Introduction Bisphosphonates (BPs) represent a very important class of compounds known for their medicinal and other properties 1, 2.
In contrast to the naturally occurring pyrophosphate P-O-P group, these compounds contain a characteristic P-C-P bridge, which is chemically and enzymatically nonhydrolyzable. BPs exhibit specific affinity towards bone, which makes them an excellent therapeutic for bone resorption diseases (especially osteoporosis, Paget’s disease, tumour induced osteolysis, hypercalcemia originated from malignancy) by inhibition of farnesyl diphosphate synthase (FPPS) and for bone tumour caused by metastatic breast tumours 3–5. The biological activity of bisphosphonates has been found to be dependent on the structure 6, lipophilicity 7, and bone binding affinity 8 of the compounds. For example, the structure of the side chain of bisphosphonates is important in determining the potency of individual bisphosphonates in biological models, and this includes a potential role for the side chain in modulating bone binding.
Crystal Lattice
The presence and position of an oxygen or nitrogen atom within the side chain of bisphosphonates are directly related to their relative potency and bone binding affinity. In general, the oxygen/nitrogen containing bisphosphonates exhibits high bone binding affinities, which might be expected to reduce efficacy. However, some of these molecules are very potent and the difference in potency has been attributed to the inhibition of FPPS.
Therefore, the structural characterization of bisphosphonates is very important tool for the elucidation of the mechanisms of the bone binding and biological activity and for the design of new, more potent compounds. Herein, we report the synthesis, solution characterization, and crystal structure of the sodium salt of tetrahydrofuranyl-2,2-bisphosphonate ( ). In the crystal the.
Medical Research
Sheldrick, SHELXL-97, A program for the refinement of crystal structures from diffraction data, University of G?ttingen, Germany, 1997. 被如下文章引用:. TITLE:. AUTHORS:,. JOURNAL NAME: DOI: Sep 16, 2014. ABSTRACT: Two new complexes, ?? and ??, have been synthesized and characterized by X-ray analysis in the course of an ongoing investigation of the;; -methyl-4,5-diphenylimidazole reaction system, aiming at understanding and assessing the relative strength and the way in which the intermolecular interactions control the supramolecular organization of these compounds. In the mononuclear complex, the benzoate ion acts as a monodentate ligand resulting in a distorted tetrahedral coordination environment.
Complex exhibits a dinuclear paddle-wheel structure; each has a square pyramidal chromophore with four benzoate oxygens in the basal plane and the pyridine-type nitrogen atom of one ligand L at the apex. The structure of is stabilized by intramolecular interactions between aromatic rings of adjacent 4,5-diphenylimidazole moieties; it is a feature also evidenced in similar compounds of the type. Introduction Imidazole and its derivatives have played a formative role in the development of coordination chemistry 1, 2. Many hundreds of neutral complexes and complex ions containing imidazoles have been prepared and characterized. The variety of spectroscopic properties and stoichiometries observed led to an improved understanding of the geometry and bonding in complexes and provided a touchstone for bonding theories. Imidazoles are particularly interesting ligands in bioinorganic 3, 4 and metallosupramolecular 5 chemistry. In the former field, imidazoles mimic the side chain of histidine and are valuable in biological modeling.
Metalloenzyme synthetic models target the enzyme active site structure, spectroscopy, and mechanism of action. Further, bioinorganic models may also lead to compounds which mimic enzyme function and provide new reagents or catalysts for practical application. In the latter field, the presence of both donor atoms to metal ions and hydrogen bond donors within imidazoles, combined with the -excessive character of the 5-membered heterocyclic ring, can lead to intermolecular assembly of metal complexes through ligand-ligand or ligand-inorganic anion interactions. In spite of the enormous scientific literature on metal complexes with simple imidazoles as ligands, there is in fact relatively little known about the coordination and metallosupramolecular chemistry of heavily substituted imidazoles 1. It is well established nowadays that the most prominent intermolecular interactions responsible for the supramolecular organization of metal complexes are hydrogen bonds and stacking interactions 6–11.
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With this in mind, an investigation has.