BACKGROUND Although the genetic basis of androgenic alopecia has been clearly established, little is known about its non-genetic causes, such as environmental and lifestyle factors. OBJECTIVE This study investigated blood and urine heavy metals concentrations, environmental exposure factors, personal behaviors, dietary intakes and the genotypes of related susceptibility genes in patients with...

Os complexos de vanádio(IV) e (V) com tartarato formados em solução e as suas possíveis interconversões foram estudados utilizando-se técnicas espectroscópicas e eletroquímicas. A investigação foi feita através de espectroscopia de NMR de V combinada com H, de NMR de C e espectroscopia de EPR. Como técnicas electroquímicas utilizaram-se a polagrografia e a voltametria cíclica. Verificou-se que ...

A new, simple, sensitive and selective catalytic method is developed for the determination of vanadium in natural and sea waters. The method is based on the catalytic effect of V(V) and/or V(IV) on the bromate oxidative-coupling reaction of metol with 2,3,4-trihydroxybenzoic acid (THBA). The reaction is followed spectrophotometrically by tracing the oxidation product at 380 and/or 570 nm after ...

The system vanadium(IV) – 4-nitrocatechol (NC) – iodonitrotetrazolium chloride (INT) water – chloroform is studied. The optimum conditions for complex formation and extraction into chloroform are found: pH=3.9-4.5 and reagent concentrations at least 2x10 mol l NC and 1.2x10 mol l INT. The composition of the ternary complex is found to be V(IV):NC:INT = 1:2:2 with maximum absorbance at 350 nm. B...

Vanadium is a transitional metal with an ability to generate reactive oxygen species in the biological system. This work was designed to assess memory deficits in mice chronically exposed to vanadium. A total of 132 male BALB/c mice (4 weeks old) were used for the experiment and were divided into three major groups of vanadium treated, matched controls, and animals exposed to vanadium for three...

SnO2 nanocrystals were prepared by precipitation in dodecylamine at 100 °C, then they were reacted with vanadium chloromethoxide in oleic acid at 250 °C. The resulting materials were heat-treated at various temperatures up to 650 °C for thermal stabilization, chemical purification and for studying the overall structural transformations. From the crossed use of various characterization technique...

Two new vanadium oxide compounds, which contain interlamellar transition metal complexes bound to vanadium oxide sheets, were synthesized hydrothermally. The crystal structure of each reveals unusual coordination geometries and interlayer bonding. [Ni(2,29-bipyridine)]2[V12O32] (1) was prepared from the reaction of V2O5, NiO, H2O and 2,29-bipyridyl in the molar ratio 4:8:3312:0.5. The isomorpho...

A large number of unexploited low-grade vanadium-titanium magnetite deposits have been found in the Chao-yang area of China in recent years. The reserves are estimated at more than 20 billion tons. A mineralogical study of raw sample indicated that it was a typical low-grade vanadium-titanium magnetite ore with weathering. Most of vanadium-titanium magnetite was replaced by martite and sphene, ...