ZfN: Search Results

1	Author	Bai Zhu, G.Wilse Robinson	Requires cookie*
	Title	Sheng
	Abstract	The structure and properties of a 1.791 molal aqueous LiF solution is investigated by performing molecular dynamics simulations using a water model with both bond flexibility and instantaneously responsive polarization. On average, each cation is in close contact with about one anion. This causes a strong overlap of the hydration shells and an almost complete breakdown of the surround ing water structure. While the lone pairs of the hydration waters in the first Li+ shell occupy preferentially tetrahedral positions, the orientational distribution of the solvent molecules around F~ is quite uniform. By comparing various autocorrelation functions of water molecules in the solution and in the pure liquid, the influence of solvated ions on the translational, rotational and vibrational motions of hydration water can be studied. M o le c u la r D y n a m ic s S tu d y o f a n A q u e o u s L iF S o lu tio n
	Reference	Z. Naturforsch. 46a, 221—228 (1991); received October 4 1990
	Published	1991
	Keywords	Hydration, Ions, Water, Solubility, Ion-pairs
	Similar Items	Find
	DEBUG INFO
	TEI-XML for	default:Reihe_A/46/ZNA-1991-46a-0221.pdf
	Identifier	ZNA-1991-46a-0221
	Volume	46

2	Author	Heinz Gamsjäger1, Harald Marhold1, Erich Königsberger1, YiJung Tsai1, Hans Kolmer2	Requires cookie*
	Title	S o lid - 3) 4 * **H20
	Abstract	S o lu te P h a s e E q u ilib ria in A q u e o u s S o lu tio n s IX . T h e rm o d y n a m ic A n a ly s is o f S o lu b ility M e a s u r e m e n ts : L a (0 H) M(C 0 Dedicated to Prof. Hitoshi Ohtaki on the occasion of his 60th birthday The aqueous solubilities of La(OH)p^(COaJjA 0.1 H20, basic lanthanum carbonate of ancylite type, have been investigated as a function of ionic strength at 25.0 °C. The stoichiometric solubility constants defined by log* K1 0 = log [La3 + ] + 1.1 log pco — 3 log [H+1 have the values 11.10, 11.32, 11.42, 11.63, and 11.70 for / = 0.1, 0.25, 1.0, 2.0, and 4.0 mol kg (Na)C104 respectively. The extrapolation to infinite dilution using the Pitzer equations resulted in a "thermodynamic" solubility constant, log* K° 0 = 10.48 ± 0.08. This in turn led to the Gibbs energy of ancylite formation: Af G f98 {La(OH)08(CO3)11 0.1 H20} = -1.531.5 kJ mol-1.
	Reference	Z. Naturforsch. 50a, 59—64 (1995); received October 1 1994
	Published	1995
	Keywords	Solubility, Carbonates, Lanthanum, Thermodynamics, Pitzer model
	Similar Items	Find
	DEBUG INFO
	TEI-XML for	default:Reihe_A/50/ZNA-1995-50a-0059.pdf
	Identifier	ZNA-1995-50a-0059
	Volume	50

3	Author	F.C M Dnessens, R.M H Verbeeck	Requires cookie*
	Title	Evidence for Intermediate Metastable States during Equilibration of Bone and Dental Tissues
	Abstract	Experimental data were collected on the solubility equilibrium of the mineral of bone, tooth enamel and calcium phosphate renal stones. Evaluation in the form of potential diagrams of Ca(OH) 2 versus H3P 0 4 shows that Ca/P ratios of 1, 4/3, 10/7, 3/2 and 5/3, related to phases like brushite, octocalcium phosphate, whitlockite, defective apatite and hydroxyapatite respectively can be important. These facts allow the interpretation that many of these calcium phosphates are present simultaneously in biominerals or that they are formed during the equilibration.
	Reference	Z. Naturforsch. 35c, 262 (1980); received December 27 1979
	Published	1980
	Keywords	Calcium Phosphates, Solubility, Bone, Dental Enamel
	Similar Items	Find
	DEBUG INFO
	TEI-XML for	default:Reihe_C/35/ZNC-1980-35c-0262.pdf
	Identifier	ZNC-1980-35c-0262
	Volume	35

4	Author	Anders Ljungqvista, Dong-M Ei Feng3, Cyril Bowers, WilliamA H Ookc, Karl Folkers3	Requires cookie*
	Title	Design, Synthesis and Biological Evaluation of Antagonists of LHRH by Criteria of Potency, Safety and Solubility
	Abstract	Some analogs o f Antide and congeners with higher water solubility have been synthesized by substitutions in positions 1, 5 or 6 with hydrophilic residues. In position 1, D -3 -Q a l has been incorporated in four peptides and D -3 -P a l in one peptide. In positions 5 and 6, D and L -3 -P a l, PzAla and (DSer)Lys have been tried. In one peptide, D -(A cD S er)L y s was substi tuted in position 6. M ost o f the new analogs had lower AOA (antiovulatory activity) than the parent com pounds but three potent analogs were identified. The first one, [N -A c -D -3 -Q a l',D p C lP h e 2,D -3 -P a l3,c-PzA C A la5,D -P ic L y s 6,ILys8,D -A l a l0]-L H R H , had 55% A O A at 0.25 ng and 100% at 0.5 /ug. Its E D 50 for in vitro histamine release was 171 ± 17 ^g/m l which is an increase from 4 9 ± 4 .8 >ug/ml for the parent com pound with N -A c -D -2 -N a l [1], The second analog, [N -A c -D -2 -N a l',D p C lP h e 2,D -3 -P a l3,PicLys5,D -(D S e r)L y s6,ILys8,D -A l a 10]-L H R H , had 69% A OA at 0.25 /ug and 95% at 0.5 fig. This analog released somewhat more histamine than the parent analog featuring D -P ic L y s6, the E D S0 being 18 //g/m l compared to 93 ± 11 for the parent analog. The third analog is: [ N -A c -D -2 -N a t 1, D pClPhe2,D -3 -P a l3,c-PzA C A la5,D -P z A la 6,ILys8,D A la ']-L H R H . The AOA for this analog was 63% at 0.25 //g and the E D 50 for histamine release 8 8 ± 6 .4 ^g/ml. histamine from mast cells [1], These features in clude a group of hydrophobic amino acids at the N-terminal and strongly basic residues in positions 6 and 8 , notably D -Arg6,Arg8. A prime example o f this class o f antagonists is [N -A c -D -2 -N a l',D -4 F -P h e 2 ,D -T rp 3, D -A rg 6] -LH R H [2], It was recently shown that some antag onists bind to rat peritoneal mast cells and mem brane preparations and that the binding was relat ed to the release of histamine [3]. We recently developed Antide (analog 1, Table III) which lacked strongly basic residues and which showed high potency and negligible histamine re lease [4], F urther evaluation of the anaphylactoid activity o f Antide concluded that Antide "repre sents a new generation of LH R H antagonists with an improved safety m argin" [5]. Prolonged duration of inhibition of gonado tropin secretion in overectomized monkeys using single [6 ] or multiple [7] doses of Antide has also been established. The same group observed a long-term supres-sion o f testosterone secretion in male monkeys after a single dose of Antide [8 ].
	Reference	Z. Naturforsch. 46b, 1231 (1991); received March 1 1991
	Published	1991
	Keywords	LH R H -A ntagonists, Antiovulatory Activity, Histam ine Release, Solubility
	Similar Items	Find
	DEBUG INFO
	TEI-XML for	default:Reihe_B/46/ZNB-1991-46b-1231.pdf
	Identifier	ZNB-1991-46b-1231
	Volume	46