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PubMed2006

Synthesis and characterization of uncapped gamma-Fe2O3 nanoparticles prepared by flame pyrolysis of ferrocene in ethanol.

Nanoparticles of iron(III) oxide were synthesized by spontaneous combustion of ferrocene in ethanol solution using a simple spirit lamp. X-ray powder diffraction and electron diffraction analysis of the powder suggested the formation of gamma-Fe2O3 (Maghemite phase) having lattice constant 8.3539 +/- 0.0209 A. Transmission Electron Micrograph suggested the formation of spherical particles with an average diameter of 24.7 +/- 1.6 nm. A sextet with an isomeric shift of 0.328 mm s(-1) seen in the Mossbauer spectrum recorded at room temperature, further supports the formation of gamma-Fe2O3. The particles were dispersed freely in the polar solvents like ethanol, dimethyl sulfoxide, and water. Infra Red spectrum gave bands at 400, 432, 565, and 638 cm(-1), which confirms the presence of gamma-Fe2O3 phase.

Crystallization↗
PubMed1996

Abuse of smoking methamphetamine mixed with tobacco. V. Plasma metabolites of N-cyanomethylmethamphetamine, a pyrolysis product formed by smoking methamphetamine in tobacco, and the species difference between mouse and rat.

N-Cyanomethylmethamphetamine (CMMA), N-formylmethamphetamine (FMA) and methamphetamine (MA) were given intraperitoneally to mouse and rat in doses of 3 mg/kg. The major metabolites of CMMA, FMA and MA in plasma were determined at short intervals after administration by GC-MS to obtain the area under the concentration-time curve (AUC). Regarding the plasma concentration of FMA after CMMA administration, a definite species difference was observed between mouse and rat. In rats given CMMA, FMA was the major component, followed by MA, amphetamine (AP), CMMA and N-formylamphetamine (FAP). In mice given CMMA, MA was a major component, followed by AP, FMA, CMMA and FAP. However, it was demonstrated that MA is also non-enzymatically produced from CMMA in plasma. Following FMA administration to rats, FMA was the major component in the plasma, showing the largest AUC value of the four metabolites, FMA, FAP, MA and AP. Following FMA administration to mice, MA showed the largest AUC value, followed by FMA, FAP and AP which were present at low levels even 5 min after injection and were scarcely detectable at 60 min. These results suggest two main mechanisms involved in the metabolism of the N-cyanomethyl group, one of which is the formation of MA by elimination of cyanoformaldehyde from N-alpha-hydroxylated CMMA and the other which is the formation of FMA by elimination of hydrogen cyanide from N-alpha-hydroxylated CMMA. The formation of FMA from CMMA was the predominant pathway in rats but not in mice.

Amphetamines↗
PubMed1990

[A neurochemical study on brain cholinergic neuron; a newly improved pyrolysis gas chromatography/mass spectrometry (PY/GC/MS) method and its application].

A new method for measuring the endogenous acetylcholine (ACh) and choline (Ch) levels using a PY/GC/MS was established, and then the alteration of cholinergic neurons in the iminodipropionitrile (IDPN) induced dyskinesia model rat brain was studied. In performing the determinations of small amounts of brain ACh and Ch levels using a curie point PY/GC/MS, the following points were improved upon in the present study: 1) We shortened the distance between the sample tube and injection port allowing the rapid transformation to an analytical system without sub-reaction and re-synthesis of demethylated products. 2) The suitable pyrolytic temperature (curie point) was adjusted to 333 degrees C. 3) Then the aqueous sample (2 microliters) was wrapped in a pyrofoil with a curie point of 333 degrees C followed by drying at 80 degrees C. Subsequently, the pyrofoil was formed by a 200 kgf/cm2 press. 4) A fused silica capillary column (DB-5) was used instead of a pre-packed column (Jenden Phase). By these improvements, both calibration curves of ACh and Ch have high linearities (r = 0.988) between 1 pmol and 2 pmol, and the apparent peak of quasi-molecular ion and less fragment ion of each Ch analog was obtained. In the globus pallidus, caudate nucleus, hippocampus and cerebellum of IDPN induced dyskinesia model rats, remarkable reductions of ACh levels were observed using our newly improved PY/GC/MS method. Thus, our improved method can be utilized for measuring ACh levels in small discrete brain regions.

Acetylcholine↗