C-HEDP

The second class, Tc-essential radiopharmaceuticals, contains those Tc-labeled substances for which the Tc atom itself greatly influences the overall physical and chemical properties of the labeled substance. The biodistribution of the 5 Tc-complex of these substances is often markedly different than the biodistribution of the substance when it is not labeled with 99 Tc. The best understood example of this class of compounds is 

From there, Tc(HIDA)2 was excreted into the bile and eventually into the intestines. Loberg also prepared C-labeled HIDA and determined its biodistribution. In marked contrast to 99 Tc(HIDA)2, C-HIDA is excreted rapidly and almost exclusively by the kidneys (7 ). The difference in distribution between HIDA and the Tc-complex of HIDA demonstrates that 5 Tc is not functioning as a tag for HIDA and illustrates some of the difficulties encountered when trying to design Tc-radiopharmaceuti-cals based on small molecules (i.e. Molecular weight 1000). 

Other members of this class of radiopharmaceuticals are listed in Table I. Although the biodistribution of some of these 9gmiTc-complexes could be predicted a priori, based on a knowledge of the fate of other metal complexes of the same ligands, it is generally difficult to predict the biodistribution of Tc-complexes when one has only a knowledge of the vivo fate of the uncomplexed ligand. 

ACS Symposium Series American Chemical Society Washington, DC, 1980. 

There are two fundamental areas where knowledge must be improved before greater studies can be expected in the development of new agents. 

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The time dependence of " C-HEDP adsorption on polycrystalline gold in the solution containing Zv is shown in Fig. 9-28 for the potential range of >200 mV. The surface excess values ( ) at a given potential reached a quasi-stationary state within... 

Figure 9-29. Potential dependence of HEDP adsorption on a sputtered polycrystalline gold electrode obtained by negative potential stepping in solutions of 0.5 moldm- NaC104 +10 mol dm C-HEDP+3x 10" mol dm" Zn(C104)2(-V-),0.5 mol dm" NaC104 + 3x10" mol dm" " C-HEDP+3 x 10" mol dm" Zn (004)2 (-0-). and 0.5 mol dm" NaOO4 + 10" mol dm" C-HEDP+3xl0" mol dm" Zn(004)2 (- -).

Phosphonates are commonly used in laundry powders at 0.5-1.0% of the powder, DTPMP and EDTMP for all uses and HEDP mostly for hardness ion control. Wash conditions for powder detergents are usually pH 9-10 and typical temperatures of 40-60 °C, although there is a strong drive to reduce this to 30 °C or even to use a cold water wash. 

Compounds 1 and 2 are closely related to each other. Both exhibit linear chain structures in which the Cu2(hedp)2 dimers are connected by edge-shared CuOs square pyramids (Fig. la). Each hedp in the chains behaves as a bis(chelating) bridging ligand and links two copper ions in a c/s-bridging mode. This is different from the traw-bridging mode... 

Zheng L.-M., Duan C.-Y, Ye X.-R., Zhang L.-Y, Wang C. and Xin X.-Q., Synthesis, crystal structure and magnetic properties of a novel mixed-valence copper phosphonate Na2Cui5(hedp)6(OH)2(H20) (hedp = 1-hydroxyethylidene- diphosphonate), J. Chem. Soc., Dalton Trans. (1998) pp. 905-908. 

The main aim of the stability studies of Re-HEDP was to determine its optimal storage conditions and shelf-life prior to its administration to patients. For this purpose, Re-HEDP was stored under different environmental conditions, namely, at 20-25°C in darkness, at 4°C in darkness, at 20-25°C in light and at 20-25°C in human serum in darkness. Instant thin layer chromatographic analysis of radiochemical purity was performed at 1,3,6,24,48 and 72 h after preparation of the Re-H EDP. 

Dange, C. et al., Desorption mechanism and dispersion efficiency of three anionic additives [polyfacrylic acid), polyfstyrene sulfonate) and HEDP] on zinc oxide, J. Colloid Interf. Sci., 315, 107, 2007. 

McRae J, Hambright P, VaUc P, Bearden AJ (1976) Chemistry of Tc-99m tracers. II. In vitro conversion of tagged HEDP and pyrophosphate (bone seekers) into gluconate (renal agent). Effects of Ca and Fe(II) on in vivo distribution. J Nucl Med 17 208-211 Pauwels EKJ, Blom J, Camps JAJ, Hermans J, Rijke AM (1983) A comparison between the efficacy of " Tc-MDP, c-DPD, c-HDP for the detection of bone metastases. Eur J Nucl Med 8 118-122... 

Figure 13. Effect of different additives on scale deposition over time (supersaturation ratio 3.05, flow rate 2 ml per second, coupon stainless steel, length 3 cm, diameter 1.3 cm, temp. 20 C, additive concentration (a) EDTP 2X10- M (b) NTMP 2X10 M (c) NDPA 10 M (d) HEDP 10 M (e) NPDA 10 M (f) EDTA 10 M (g) NTA 10 M (h) no additive)...

Figure 9-7 shows the iron concentration of test solutions as a function of the HEDP concentration at the end of gravimetric measurements (24 h) (Kalman et al., 1994). The iron content was determined separately in dissolved and precipitated (rust) form. The variation of total iron content is in accordance with the corrosion rate of carbon steel, showing a minimum curve. At lower HEDP concentrations, high amounts of iron exist in the form of rust, indicating a corrosion protection effect of the oxide layer on the carbon steel surface. At higher concentrations (c> 10 M), HEDP keeps the total amount of iron in the solution phase. These results indicate that complex formation between HEDP and iron ions has an important effect on the inhibition effect of HEDP. The... 

Figure 9.8. Concentration distribution curves for the complexes formed in the Fe(II)-HEDP system as a function of pH C iga d=3x 10 mol dm" at the Fe/ HEDP molar ratio of 0.5.

Figure 9-26. STM image of Au(ll I) surface in 1.5xl(T M HEDP+I.5x IO" MZn +0.1 M NaC104 solution a) beginning of the polymer film formation after two oxidation-reduction cycles at 900 mV (NHE), b) at 1300 mV (NHE), c) in the zinc reduction range, and d) after five oxidation-reduction cycles at 1300 mV (NHE).

Four types of oxygen chemical state can be clearly distinguished from the altering shape of the O Is line related to 0-Fe (530.2 eV), HO-Fe (531.4eV), 0-P (532.3 eV), and adsorbed H2O (533.2 eV) environments. The 01s component for the HO-C environment, measured in solid HEDP, appeared at... 

Figure 9-41. 01s photoelectron spectra of mild steel surface formed after 30 min immersion in neutralized HEDP solution a) 10" M HEDP, b) 10 M HEDP, and c) 10 M HEDP adsorption. 

Figure 9-46. O Is photoelectron spectra of a mild steel surface treated in different Zn/HEDP molar ratios in the solutions a) Zn/HEDP molar ratio = 0.5, b) Zn/HEDP molar ratio = 1, c) Zn/HEDP molar ratio = 2, and d) Zn/HEDP molar ratio = 3.

Phosphonic acid-based chemicals such as ATMP, HEDP, DTMP, and their sodium salts were added to portland cement in dosages of 0.03-0.09% at a constant w/c ratio of 0.35 and their conduction calorimetric and DSC curves were compared. The conduction calorimetric curves... 

Complexation and pyrolysis is another soft chemistry method to prepare nano-LiFeP04. LiOH H2O, Fe(N03)-9H20, and l-hydroxyethylidene-1,1-diphosphonic acid [CFl3C(0H)(H2P03)2 HEDP] are mixed in a molar ratio of 2 2 1, and ethylene glycol is used as a carbon source. After heating the precursors at 700°C for 5 h, a nano-LiFeP04/C material in the 50-300 nm... 

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