Hydrogen incorporation in Ni–P films prepared by electroless deposition

Electroless NiP films, with 12 to 16 wt % P, were deposited from a moderately acid solution. Thermogravimetric analysis indicates the presence of occluded hydrogen in the layers, which desorbs upon heating. The amount of incorporated hydrogen decreases when the pH of the solution or the nickel sulfate concentration is increased; by contrast it increases with hypophosphite concentration. Cyclic voltammetry, using an electrochemical quartz crystal microbalance, confirms the existence of parasitic reactions, namely the reduction of protons of the solvent during the cathodic process and oxidation of hydrogen during the dissolution of the layers. This behaviour is in qualitative agreement with the proposed reaction scheme.     

Tuberculosis associated haemophagocytic syndrome: two cases with a favourable outcome

Haemophagocytic syndrome is a heterogenous disease characterized by disordered macrophage activation associated with viral, bacterial or parasitic infection. The few reports of haemophagocytosis occurring in the presence of mycobacterial infection show a high mortality rate and we present two further cases notable for their favourable issue. Rapidity of diagnosis and immediate treatment could explain the avoidance of a fatal outcome.     

Characterisation of electrodeposited nanocrystalline Ni–Mo alloys

Ni–Mo nanocrystalline layers were electrodeposited using direct current from citrate–ammonia solutions. The quartz crystal microbalance investigation confirms that the discharge process starts with hydrogen evolution before the onset of the alloy deposition. The grain size was estimated from X-ray line broadening. It decreases when the molybdenum content is increased. It is smaller for layers deposited at pH 9.5 than 8.5. The microhardness exhibits a maximum close to 800 Vickers for _Mo around 17 wt%. For higher _Mo a softening is observed showing a deviation from Hall-Petch behaviour due to small grain size. In deaerated hydrochloric solutions, the layers show a large passivation domain without any pitting. The corrosion currents as well as the passivation currents, higher than for the bulk Hastelloy B alloy, decrease when _Mo is increased.     

Arthrotic sciatica caused by radicular compression of osteophytic origin in the lateral recess. Apropos of 18 cases

The authors report 18 cases of arthrosic sciatica due to toot compression in the lateral recess by posterior corporeal and/or posterior apophyseal osteophytosis. The authors study the clinical and radiological characteristics that may indicate the diagnosis and discuss the different mechanisms by which vertebral arthrosis can lead to radicular compression. When surgery is necessary because of the persistent nature of the sciatica, a broader approach should be undertaken than that required for excision of the disc, in order to explore fully the roots, the multiplicity of possible compression sites being one of the essential characteristics of these cases of arthrosic radiculopathy. Study of the literature and of the series of sciatica patients operated upon by the authors shows that although discal hernia is far from being the most frequent cause of common sciatica, arthrosic compression is a cause that cannot be ignored, especially in aged subjects.     

Reduction of Zr (IV) in (KCl/NaCl) eutectic (50/50 mol%) containing KF/ZrCl4 in molar ratios of 6/1 or 4/1 at 750° C. Characterization of the dissolved species by IR spectroscopy

Infrared analysis of baths which are mixtures of (KCl/NaCl) (50/50) with KF and ZrCl₄ in the molar ratio 4 or 6, indicates that the species present at 750° C are ZrF₄ and K₃ZrF₇. Voltammetric study of these melts containing 1 wt % Zr shows that ZrF₄ reduces in three steps: ZrF₄ ZrF₂, ZrF₄ Zr, ZrF₂ Zr, whilst K₃ZrF₇ is reduced via: K₃ZrF₇ Zr or K₃ZrF₇ ZrF₂, ZrF₂ Zr. It appears that ZrF₄ vanishes completely by increasing the KF/ZrCl₄ ratio until the KF concentration is able to stabilize K₃ZrF₇ in the melt.     

Study of Ti(III) solutions in various molten alkali chlorides. I. Chemical and electrochemical investigation

The effect of alkali metal cations in molten chloride baths on the behaviour of Ti(III) in these melts has been studied. With caesium chloride the percentage of total dissolved titanium present as Ti(II) after 72 hours at 700° C is 0.1%, whereas in lithium chloride it is 2%. In the presence of excess titanium metal the proportion of Ti(II) is always much higher. In LiCl it depends strongly on the area of titanium exposed and may reach 85%. In CsCl, on the other hand, this factor has no effect since a fine dispersion of powdery titanium appears at the very beginning of the reaction. The amount of Ti(II) remains close to 50%. In all the baths studied, the electrochemical reduction of Ti(III) at 700° C occurs in two steps: Ti(III) + e Ti(II)E _1/2 = – 1.6V versus Cl^–/Cl₂ Ti(II) + 2e Ti(O)E _1/2=–2.1V versus Cl^–/Cl₂. These results are different from those previously obtained in CsCl-LiCl (40–60 mol%) at 400° C, where reduction is a one-step process.     

Peptide-grafted nanodiamonds: preparation, cytotoxicity and uptake in cells

Nanodiamonds that were prepared by high pressure/high temperature were functionalized with biomolecules for biological applications. Nanodiamonds (NDs, < or =35 nm) that were coated by silanization or with polyelectrolyte layers were grafted with a fluorescent thiolated peptide via a maleimido function; this led to an aqueous colloidal suspension that was stable for months. These substituted NDs were not cytotoxic for CHO cells. Their capacity to enter mammalian cells, and their localisation inside were ascertained after labelling the nucleus and actin, by examining the cells by confocal, reflected light and fluorescence microscopy.