A sodalite-like framework based on octacyanomolybdate and neodymium with guest methanol molecules and neodymium octahydrate ions.
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Structure and mesomorphism of neodymium(III) alkanoates.
The structural and thermal behavior of all members of the homologous series of neodymium(III) alkanoates, ranging from neodymium(III) butyrate to neodymium(III) eicosanoate are described. Neodymium(III) butyrate monohydrate, Nd(C3H7COO)3.H2O crystallizes in space group P1 (No. 2), Z = 2. The lattice parameters are a = 9.824(2) A, b = 11.974(2) A, c = 14.633(2) A, alpha = 86.21(2) degrees, beta = 75.92(2) degrees, gamma = 77.97(2) degrees. The crystal structure consists of ionic layers of neodymium ions, separated by bilayers of butyrate anions. In the ionic layers, the neodymium ions are connected by bridging tridentate carboxylate groups to zigzag chains, whereas the chains are connected among themselves by bridging bidentate carboxylate groups. The two crystallographically different neodymium ions are both having coordination number 9, with a geometry close to a monocapped square antiprism. The structure of the higher homologues can be derived from the structure of neodymium butyrate by extending the alkyl chains. These compounds have a lamellar bilayer structure with planes of neodymium(III) ions coordinated to the carboxylate groups and with the alkyl chains in an all-trans conformation. All homologous compounds from neodymium(III) pentanoate to neodymium(III) pentadecanoate display a thermotropic mesophase, which was identified by high-temperature X-ray diffraction as a smectic A phase. For the series from neodymium(III) pentanoate to neodymium(III) undecanoate an additional high viscosity mesophase is present between the crystalline state and the smectic A mesophase.
Journal Article↗
Selective recognition of neodymium (III) using ion imprinted polymer particles.
Neodymium (III) ion-imprinted polymer (IIP) materials were prepared by the copolymerization of neodymium (III)-5,7-dichloroquinoline-8-ol-4-vinylpyridine ternary complex with styrene(monomer), divinyl benzene (crosslinking monomer) in the presence of 2,2'-azobisisobutyronitrile (initiator). The synthesis was carried out in 2-methoxy ethanol medium (porogen) and the resultant material was filtered, washed, dried and powdered to form unleached IIP particles. The imprint ion was removed by stirring the above particles with 50% (v/v) HCl for 6 h to obtain leached IIP particles with cavities in the polymer particles. Control polymer (CP) particles were similarly prepared without imprint ion, i.e. neodymium (III). CP, unleached and leached IIP particles were characterized by TLC, IR, microanalysis, XRD and UV-visible spectrophotometric studies. The preconcentration of 5-150 microg of neodymium (III) ions present in 500 ml of solution was possible with as little as 40 mg of neodymium (III) IIP particles in the pH range 7.5-8.0 with a detection limit of 50 ng/l. Five replicate determinations of 25 microg of neodymium (III) present in 500 ml of solution gave a mean absorbance of 0.120 with a relative standard deviation of 2.65%. The imprinting effect of IIP particles was noticed in all preconcentration and selectivity studies when compared with CP particles. Furthermore, the selectivity coefficients of neodymium (III) IIP particles were much higher compared with the reported separation factors for the best liquid-liquid extractants, viz. di-2-ethylhexyl phosphoric acid and 2-ethylhexyl-ethylhexyl phosphonate. Kinetic and isotherm studies during rebinding of neodymium (III) onto IIP particles were also carried out.
Ions↗
A comparison of neodymium: YAG and argon laser iridotomies.
A prospective short-term clinical study evaluated argon and Q-switched neodymium:YAG laser iridotomies in 40 eyes of 20 patients with primary chronic angle-closure glaucoma. All patients had bilateral iridotomies with one eye randomly assigned to argon laser and the fellow eye to neodymium:YAG laser therapy. In all eyes a patent iridotomy was created in one treatment session. A mean of 12 +/- 11 and 0.033 +/- 0.025 J were needed for iridotomy formation in argon and neodymium:YAG treated eyes respectively. No neodymium:YAG and six (30%) argon iridotomies had marked closure requiring retreatment. Immediate postoperative intraocular pressure elevation greater than 10 mmHg was seen in seven (35%) argon and six (30%) neodymium:YAG-treated eyes. Nine (45%) eyes treated with the neodymium:YAG laser had bleeding from the iridotomy site. No acute lens damage was found in the neodymium:YAG eyes while seven (35%) lenses in the argon group had focal opacities. Seven (35%) neodymium:YAG and five (25%) argon treated eyes had focal nonprogressive corneal opacities above the iridotomy site. Specular microscopy showed a significant central corneal endothelial loss in argon laser treated eyes. No eyes had detectable retinal damage.
Adult↗
Visible absorption spectra of the 4f electron transitions of neodymium, praseodymium, holmium and erbium complexes with fleroxacin and their analytical application.
The absorption spectra of the 4f electron transitions of neodymium, praseodymium, holmium and erbium complexes with fleroxacin in the presence of cetylpyridinium chloride were studied by normal and derivative spectrophotometry. Their molar absorptivity at the maximum absorption bands are about 5.3 (at 571 nm) times greater for neodymium, 2.8 (at 483 nm) times greater for praseodymium, 12.6 (at 448.5 nm) times greater for holmium and 9.7 (at 519 nm) times greater for erbium than those in the absence of complexing agents. The second-derivative spectrum is used both to eliminate the interference from other rare earths and to improve the sensitivity. Beer's law is obeyed from 3.0 - 70 microg ml(-1) for neodymium and holmium, from 6.0 - 70 microg ml(-1) for erbium, and from 12.0 - 70 microg ml(-1) for praseodymium. The relative standard deviations are 1.9% and 1.5% for 7.5 microg ml(-1) of neodymium and holmium, and 2.1% and 1.6% for 15.0 microg ml(-1) of praseodymium and erbium, respectively. Their detection limits (signal-to-noise ratio = 2) are 3.2 microg ml(-1), 1.3 microg ml(-1), (1.1) microg ml(-1) and 2.5 microg ml(-1) for praseodymium, neodymium, holmium and erbium, respectively. A new system for the simultaneous determinations of the praseodymium, neodymium, holmium and erbium in rare earth mixtures with good accuracy and selectivity is proposed.
Journal Article↗
Cytotoxic activity of new neodymium (III) complexes of bis-coumarins.
Complexes of neodymium (III) with bis-coumarins: 3,3'-benzylidene-bis(4-hydroxy-2H-1-benzopyran-2-one); bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-piridin-2-yl-methane; bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-piridin-4-yl-methane; bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-(1H-pyrazol-3-yl)-methane were synthesized by reaction of neodymium (III) salt and the ligands, in amounts equal to metal:ligand molar ratio of 1:2. The complexes were prepared by adding an aqueous solution of neodymium (III) salt to an aqueous solution of the ligand subsequently raising the pH of the mixture gradually to ca. 5.0 by adding dilute solution of sodium hydroxide. The neodymium (III) complexes with bis-coumarins were characterized by different physicochemical methods-elemental analysis, IR-, (1)H- and (13)C-NMR-spectroscopies and mass-spectral data. The spectral data of neodymium (III) complexes were interpreted on the basis of comparison with the spectra of the free ligands. This analysis showed that in the Nd (III) complexes the ligands coordinated to the metal ion through both deprotonated hydroxyl groups. On the basis of the nu(C=O) red shift observed, participation of the carbonyl groups in the coordination to the metal ion was also suggested. Cytotoxic screening by MTT assay was carried out. The complexes were tested on HL-60, HL-60/Dox and SKW-3 cell lines. The overall results from the preliminary screening program revealed that all of the new Nd (III) complexes reach 50% inhibition of the malignant cells proliferation and thus could be considered as biologically active. On the basis of the IC(50) values obtained compounds Nd(L(1))(OH).H(2)O and Nd(L(3))(OH).2H(2)O were found to exert superior activity in comparison to the remaining complexes.
Adult↗
Absolute isotopic composition and atomic weight of neodymium using thermal ionization mass spectrometry.
Synthetic mixtures prepared gravimetrically from highly enriched isotopes of neodymium in the form of oxides of well-defined purity were used to calibrate a thermal ionization mass spectrometer. A new error analysis was applied to calculate the final uncertainty of the atomic weight value. Measurements on natural neodymium samples yielded an absolute isotopic composition of 27.153(19) atomic percent (at.%) 142Nd, 12.173(18) at.% 143Nd, 23.798(12) at.% 144Nd, 8.293(7) at.% 145Nd, 17.189(17) at.% 146Nd, 5.756(8) at.% 148Nd, and 5.638(9) at.% 150Nd, and the atomic weight of neodymium as 144.2415(13), with uncertainties given on the basis of 95% confidence limits. No isotopic fractionation was found in terrestrial neodymium materials.
Hot Temperature↗
UV and fluorescence spectral changes induced by neodymium binding of N,N'-ethylenebis[2-(o-hydroxyphenolic)glycine] and N,N'-di(2-hydroxybenzyl)ethylenediamine-N,N' diacetic acid.
In 0.01 M 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (Hepes), pH 7.4 and room temperature, the binding of neodymium to N,N'-ethylenebis[2-(o-hydroxyphenolic)glycine] (EHPG), or N,N'-di(2-hydroxybenzyl)ethylenediamine-N,N' diacetic acid (HBED) had been studied from 210 to 330 nm by means of difference UV spectra. Two peaks at 240 and 292 nm appear in difference UV spectra after neodymium binding to EHPG or HBED. The 1:1 stable complex can be confirmed from spectral titration curves. The molar extinction coefficient of Nd-EHPG and Nd-HBED complexes are Deltaepsilon(Nd-EHPG)=(12.93+/-0.21) x 10(3)cm(-1)M(-1), Deltaepsilon(Nd-HBED)=(14.45+/-0.51) x 10(5)cm(-1)M(-1) at 240 nm, respectively. Using EDTA as a competitor, the conditional equilibrium constants of the complexes are logK(Nd-EHPG)=11.89+/-0.09 and logK(Nd-HBED)=12.19+/-0.15, respectively. At the same conditions, fluorescence measurements show that neodymium binding to EHPG leads to a quenching of the fluorescence of EHPG at near 310 nm. However, there is no obvious fluorescence change of HBED at 318 nm with the binding of neodymium to HBED.
Edetic Acid↗
Treatment of spider veins using a 10 millisecond pulse-duration frequency-doubled neodymium YAG laser.
BACKGROUND: The pulsed dye laser has been the standard for treating vascular lesions. Although quite effective for treating facial vessels and port-wine stains, spider veins of the lower extremities are more difficult to treat. Recent studies have shown that lasers with longer pulse durations are more effective at treating spider veins. A new long-pulse frequency-doubled Neodymium:YAG laser has been developed with a 10-ms pulse duration and sufficient energy to enable treatment with a 3- or 4-mm diameter treatment beam. OBJECTIVE: To determine the effectiveness of the long pulse Neodymium:YAG laser for treating spider veins of the lower extremities. METHODS: Spider veins less than 0.75 mm in diameter on the legs of 15 female volunteers were treated in 1 or 2 areas. Treatments were administered through a water-cooled chill tip using the frequency-doubled Neodymium:YAG laser with a 10-ms pulse duration. A dose of 16 J/cm2 was administered, completing 3 passes over each visible vein during each session, for a total of 2 sessions administered 6 weeks apart. Photographs of treatment areas were digitally analyzed for degree of vessel clearance. RESULTS: Computer-based image analysis revealed clearing of over 75% of veins following 2 treatments with 16 J/cm2. Side effects were minimal, and the treatments were well tolerated. CONCLUSIONS: The 532 nm, 10 ms pulse duration, frequency-doubled Neodymium:YAG laser is safe and effective for treating spider veins of the lower extremities less than 0.75 mm in diameter, in patients with Fitzpatrick skin Types I-III.
Adult↗
[Histological changes following endovesical neodymium-YAG-laser irradiation (author's transl)].
Experimental animal research was used to compare the coagulatory qualities of the argon laser and the Neodymium-YAG laser to results obtained through electrocoagulation. The argon laser effects a necrosis near the urinary bladder wall surface, and when the energy density is increased, it may ablate the tissue to the point of perforation. In contrast, the Neodymium-YAG laser effects a bandshaped necrosis that penetrates all layers of the urinary bladder wall without primarily resulting in an ablation of tissue. Electrocoagulation results in irregularly demarcated necroses of varying depths, which can be explained by the uncontrolled flow of the high-frequency currents according to the paths of least resistance. The Neodymium-YAG laser is the one most suited for transmural coagulation of defined areas within the urinary bladder wall due to the even spread of its thermal energy that is independent of the affected tissue structure, as well as to its deep coagulatory qualities which in turn are due to the laser's minimal tissue absorption. The Neodymium-YAG laser allows the setting of reproduceable, sharply demarcated necroses into the bladder wall with an ensuing complete destruction of all wall layers. The wall framework within the necrotic area, however, remains intact, so that the danger of perforation is kept at a minimum.
Animals↗
[Effect of neodymium on the crystal structure of human dental enamel in vitro].
The possibility of neodymium incorporation into hard tissues of permanent teeth has been investigated. The amount of neodymium was determined by X-ray microprobe analysis. The result indicates that different phases of enamel apatite have been recristallised. Neodymium compounds have appeared while the amount of some minerals in enamel have decreased. Neodymium could be an effective agent in stabilization of the apatite structure of dental enamel.
Crystallization↗
Interactions between metal ions and carbohydrates. The coordination behavior of neutral erythritol to neodymium ion.
A single crystal of a coordinated complex of neutral erythritol (C4H10O4,E) with a neodymium ion, NdE(II), was synthesized and studied using FT-IR and X-ray diffraction analysis. In NdE(II) (NdCl3.2.5C4H10O4.C2H5OH) the Nd3+ coordinates with one chloride ion and eight OH groups from three erythritol molecules. There are two neodymium centers linked by one erythritol molecule with same coordination structure in the molecule. Two erythritol molecules provide 1,3,4-hydroxyl groups to coordinate with a neodymium ion; another erythritol molecule coordinates to two Nd ions via its 1,2-hydroxyl groups and 3,4-hydroxyl groups, respectively. The OH groups of erythritol act as ligand to coordinate to neodymium ions, and OH groups of erythritol form hydrogen bond networks that link chain and layer together to build three-dimensional structures. The ratio of metal to ligand is 1:2.5. The structure of NdE(II) is more complicated than the previously reported NdE(I), which is NdCl3.C4H10O4.6H2O; in NdE(I), Nd3+ is coordinated to four hydroxyl groups from two erythritol molecules, four water molecules and one chloride ion. The results indicate the complexity of metal-sugar interaction.
Journal Article↗
Comparison of retinal photocoagulation using pulsed frequency-doubled neodymium-YAG and argon green laser.
The photocoagulation effects on retinal and choroidal tissue of the argon green and pulsed frequency-doubled neodymium-YAG lasers were examined in rabbit eyes. In contrast to the continuous wave output of the argon green laser, the pulsed frequency-doubled neodymium-YAG laser produces a series of 1 microsecond pulses emitted at a repetition rate of 10 kHz. The high repetition rate results in pulse averaging, allowing relatively low peak powers to be used while producing average powers capable of thermal tissue effects. Photocoagulation lesions in the rabbit retina were placed in pairs using each of the lasers. Light microscopic comparison of the argon and neodymium-YAG burns revealed morphologically similar lesions for up to 14 days after photocoagulation, with damage predominantly at the level of the retinal pigment epithelium and outer retina. The high repetition rate, pulsed frequency-doubled neodymium-YAG laser produced thermal tissue effects similar to the continuous wave argon green laser.
Animals↗
[Intraocular pressure results of contact transscleral cyclophotocoagulation with Neodymium YAG laser for refractory glaucoma].
PURPOSE: To evaluate the effects of contact transscleral cyclophotocoagulation with neodymium YAG laser for refractory glaucoma. METHOD: This was a retrospective study with 36 patients (37 eyes) who were treated at the Rouen Hospital from February 1996 to February 2001. Patients had various types of glaucoma: glaucoma in pseudophakia (12), primary open-angle glaucoma (16), posttraumatic glaucoma (6), glaucoma associated with uveitis (4), neovascular glaucoma (3), and glaucoma after silicone oil (1). The Neodymium YAG laser (Alcon) was used for treatment. Energy was delivered in up 32 applications of 7-9 W for 0.7 seconds each. All patients except one 10-year-old child received retrobulbar anesthesia. Intraocular pressure was measured after 4 hours, 1 month, and 10 years. RESULTS: The mean preoperative intraocular pressure of 30.3 (+/-1.3) mmHg decreased to 19.4 (+/-2) mmHg at 1 month and to 22.2 (+/-2.4) mmHg at 1 year. Seven patients underwent a second treatment during the year, since the first one was insufficient. Treatment lowered the number of medications used to decrease intraocular pressure from a pretherapy mean of 2.7 mmHg to 1.8 mmHg at 1 month and 2.07 mmHg at 1 year. In three patients who were treated for a painful sightless eye, the treatment failed. DISCUSSION: Neodymium YAG laser necroses ciliary bodies. Treatment must be dosed to achieve the greatest efficacy without hypotonia, although hypotonia is rare, as is non-response to treatment. A few patients will be retreated during the year. The subgroup of sightless painful eyes had a high failure rate (75%), with half undergoing evisceration. We found no other differences according to the origins of refractory glaucoma. CONCLUSION: Midterm results of contact transscleral cyclophotocoagulation with Neodymium YAG laser are encouraging in the treatment of refractory glaucoma.
Adolescent↗
Lithotripsy of gallstones by means of a quality-switched giant-pulse neodymium:yttrium-aluminum-garnet laser. Basic in vitro studies using a highly flexible fiber system.
The quality-switched neodymium:yttrium-aluminum-garnet laser represents a new instrument for athermal fragmentation of gallstones by transformation of optical energy into mechanical energy in the form of shock waves via local plasma formation. A highly flexible 300-micron fiber transmission system was used in basic investigations to determine the influence of varying pulse repetition rates (5-30 Hz) and pulse energies (15 and 20 mJ) on shock wave intensity and stone fragmentation in vitro for 105 biliary calculi of known size and chemical composition. After performance of 1200 shock wave pressure measurements using polyvinylidenefluoride hydrophones, stone fragmentation was analyzed by determination of fragment removal rates (volume of fragments removed per fragmentation time), ablation rates (mean volume removed per laser pulse), and median fragment sizes for each laser setting. With the quality-switched neodymium:yttrium-aluminum-garnet laser system, all concrements could be reliably disintegrated into small fragments (median diameter, 0.7-1.7 mm). Compared with pure cholesterol stones, a significantly higher fragment removal rate was achieved in cholesterol stones containing 30% calcium phosphate (P = 0.039), in cholesterol stones containing 20% pigment (P = 0.015), and in pure pigment stones (P = 0.007). Fragment removal rates, local shock wave pressures, and median grain sizes were significantly higher at a pulse energy of 20 mJ than with 15 mJ. Shock wave pressures showed a distinct dependence on pulse repetition rates at 20 mJ, yet not at 15 mJ. Because there is no evident hazard of thermal damage to tissue using the quality-switched neodymium:yttrium-aluminum-garnet laser, it appears to be a promising device for nonsurgical biliary stone therapy.
Aluminum↗
Theoretical and spectroscopic evidence for coordination ability of 3,3'-benzylidenedi-4-hydroxycoumarin. New neodymium (III) complex and its cytotoxic effect.
Theoretical and spectroscopic studies of 3,3'-benzylidenedi-4-hydroxycoumarin (bhc) have been performed. B3LYP/6-31G* calculations reproduced the experimental molecular structure of bhc and showed two O-H...O asymmetrical intramolecular hydrogen bonds with O...O distances 2.638 and 2.696 A. The calculated Fukui functions and Molecular Electrostatic Potential for bhc and its deprotonated form, bhc(2-), predicted that the most probable reactive sites for electrophilic attack and hydrogen bonds are the carbonyl oxygens, followed by the hydroxyl oxygens. The coordination ability of 3,3'-benzylidenedi-4-hydroxycoumarin has been proved in a complexation reaction with neodymium (III) ion. The new neodymium (III) complex of bhc was studied by elemental analyses, conductivity and other physical properties, mass spectra, (1)H, (13)C NMR, UV-Vis and IR spectroscopy. The data obtained are in agreement with the metal:ligand ratio of 1:1, and the formula Nd(bhc(2-))(OH)(H(2)O), where bhc(2-)=C(25)H(14)O(6)(2-). The vibrational analysis of the neodymium (III) complex, free bhc, and its monomeric building block, 4-hydroxycoumarin, showed that in the Nd(III) complex the ligand coordinates to the metal ion through both deprotonated hydroxyl groups. The participation of both carbonyl groups in coordination to the metal ion was confirmed by the significant shift of nu(C=O) to lower wavenumber. The evaluation of the cytotoxic activity of the new Nd(III) complex on SKW-3 and HL-60/Dox cells revealed, that it is a potent cytotoxic agent and should be subset further to more detailed pharmacological and toxicological study.
4-Hydroxycoumarins↗
One hundred neodymium-YAG laser ablations of obstructing tracheal neoplasms.
Forty patients with obstructing, nonresectable tracheal neoplasms underwent 100 ablations with the neodymium-yttrium-aluminum garnet (YAG) laser. The laser allows bloodless resection and vaporization of tumors. Unlike the carbon dioxide laser, the neodymium-YAG laser can be used with the flexible bronchoscope and has an excellent effect on coagulation. Thirty-four patients had primary lung malignancies (epidermoid in 24); 4 had metastatic malignancies; and 2 had benign lesions. Results have been excellent in 22, fair in 10, and poor in 8. No patient has died or had a deleterious result. Complications have occurred in only 1 of 89 ablations done with the flexible bronchoscope. We believe that the neodymium-YAG laser is effective in opening major tracheal or bronchial obstructions and offers substantial symptomatic improvement in patients who are short of breath. Although this treatment is only palliative, the results have been excellent in more than half of the patients.
Aged↗
Photoacoustic spectroscopy study of neodymium complexes with alanine, valine, phenylalanine and tryptophan.
Neodymium complexes with amino acids: Nd(Ala)(3)Cl(3).3H(2)O, Nd(Val)(3)Cl(3).3H(2)O, Nd(Phe)Cl(3).5H(2)O and Nd(Trp)(3)Cl(3).3H(2)O (Ala: L-alanine, Val: L-valine, Phe: L-phenylalanine, Trp: L-tryptophan) are synthesized and their photoacoustic (PA) spectra are reported. The nephelauxetic ratio beta, bonding parameter b(1/2) and Sinha parameter delta are calculated based on their PA spectra. The variation of these parameters and correlation of them with the nature of metal-ligand bonding are discussed. The PA intensity analysis of the f-f transitions of neodymium ion is carried out by calculating the intensity branching vector. The environmental effect on the f-f transitions of neodymium ion is also studied. The branching vectors of the f-f transitions of Nd(Ala)(3)Cl(3).3H(2)O and Nd(Val)(3)Cl(3).3H(2)O are similar, which indicates the perturbation of the two ligand fields is similar. The branching vectors of energy levels 4G(5/2)+(2)G(7/2) of Nd(Phe)Cl(3).5H(2)O and Nd(Trp)(3)Cl(3).3H(2)O increase remarkably compared with those of Nd(Ala)(3)Cl(3).3H(2)O and Nd(Val)(3)Cl(3).3H(2)O. As the degree of covalency increases, the oscillator strength of the hypersensitive transition exhibits a corresponding increase. The relaxation process of Nd(Ala)(3)Cl(3).3H(2)O is established through its PA and electron absorption spectroscopy (EAS). A method used to resolve the PA amplitude spectrum is suggested. With the phase spectrum, PA absorption bands of Nd(Trp)(3)Cl(3).3H(2)O are resolved well in the region of ligand absorption.
Absorption↗