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Biomedical subjects

C L Qiu

Publications and source records attributed to C L Qiu.

10 recordsLinked to original sources
PubMed2005

The effect of Nb addition on mechanical properties, corrosion behavior, and metal-ion release of ZrAlCuNi bulk metallic glasses in artificial body fluid.

Bulk metallic glasses (BMGs) of Zr(65 - x)Nb(x)- Cu(17.5)Ni(10)Al(7.5) with Nb = 0, 2, and 5 at % were prepared by copper mold casting. Compression tests reveal that the two BMGs containing Nb exhibited superior strength and plasticity to the base alloy. The corrosion behavior of the alloys obtained was investigated in artificial body fluid by electrochemical measurements. It was found that the addition of Nb significantly enhanced the corrosion resistance of the Zr-based BMG, as indicated by a remarkable increase in corrosion potential and pitting potential. XPS analysis revealed that the passive film formed after anodic polarization was enriched in aluminum oxide and depleted in phosphate ions for the BMGs containing Nb, which accounts for the improvement of corrosion resistance. On the other hand, metal-ion release of different BMGs were determined in PPb (ng/mL) level with inductively coupled plasma mass spectrometry (ICP-MS) after being immersed in artificial body fluid at 37 degrees C for 20 days. It was found that the addition of Nb considerably reduced the ion release of all kinds of metals of the base system. This is probably attributed to the promoting effect of Nb on a rapid formation of highly protective film.

Aluminum↗
PubMed1990

[Influence of plasma alpha-human atrial natriuretic polypeptide on natriuretic and diuretic effects in patients with nephrotic syndrome].

The physiological mechanism regulating secretion of alpha-human atrial natriuretic polypeptide (alpha hANP) was studied by measuring plasma alpha hANP (P alpha hANP) with radioimmunoassay during water immersion (WI). Twelve healthy volunteers and sixteen patients with nephrotic syndrome were immersed in water for 4 hours. During WI, alpha hANP level and urinary cGMP excretion (UcGV) increased significantly both in volunteers and patients, the urinary volume (UV) and urinary Na excretion (UNaV) also increased significantly. The mean peak values of alpha hANP and UcGV in volunteers were significantly lower than those in the patients, whereas the mean values of UV and UNaV in the former were significantly higher than those in the latter. The increase in alpha hANP level in volunteers correlated positively with the increase of UNaV, UV and UcGV during WI. The close correlations between the increased alpha hANP level and the increased UNaV, UV and UcGV was shown in the patients. These results suggest that alpha hANP is released into the circulation by acute central hypervolemia and plays a physiologically important role in maintaining water and electrolytes homeostasis in normal subjects and that the increased alpha hANP level in nephrotic syndrome makes compensatory regulation in water and electrolytes disorders.

Adolescent↗