Repair and Manufacture of High Performance Products for Medicine and Aviation with Laser Technology

High performance products used for special purposes in medicine and aviation are often manufactured from advanced materials such as titanium and nickel based alloys. As the most promising and effective technology for such production and repair the Laser Rapid Prototyping technologies are being used and implemented into the practice. Special focus has been orientated into the Laser Net Shape (LENS) technology. This paper will review the State of the Art of the LENS laser technology and present application case studies where LENS is being applied to manufacture of modern medical implants such as bone fixation plate and jet engine turbine inconel blade

PKD1 and PKD2 mutations in Slovenian families with autosomal dominant polycystic kidney disease

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a genetically heterogeneous disorder caused by mutations in at least two different loci. Prior to performing mutation screening, if DNA samples of sufficient number of family members are available, it is worthwhile to assign the gene involved in disease progression by the genetic linkage analysis. METHODS: We collected samples from 36 Slovene ADPKD families and performed linkage analysis in 16 of them. Linkage was assessed by the use of microsatellite polymorphic markers, four in the case of PKD1 (KG8, AC2.5, CW3 and CW2) and five for PKD2 (D4S1534, D4S2929, D4S1542, D4S1563 and D4S423). Partial PKD1 mutation screening was undertaken by analysing exons 23 and 31–46 and PKD2 . RESULTS: Lod scores indicated linkage to PKD1 in six families and to PKD2 in two families. One family was linked to none and in seven families linkage to both genes was possible. Partial PKD1 mutation screening was performed in 33 patients (including 20 patients from the families where linkage analysis could not be performed). We analysed PKD2 in 2 patients where lod scores indicated linkage to PKD2 and in 7 families where linkage to both genes was possible. We detected six mutations and eight polymorphisms in PKD1 and one mutation and three polymorphisms in PKD2. CONCLUSION: In our study group of ADPKD patients we detected seven mutations: three frameshift, one missense, two nonsense and one putative splicing mutation. Three have been described previously and 4 are novel. Three newly described framesfift mutations in PKD1 seem to be associated with more severe clinical course of ADPKD. Previously described nonsense mutation in PKD2 seems to be associated with cysts in liver and milder clinical course

New antioxidants for treatment of transition metal containing inks and pigments

Corrosive iron and copper ions and acids in iron gall inks and in certain pigments such as verdigris and malachite lead to enhanced degradation of paper. A recent EC co-funded project "InkCor" proposed the use of tetraalkylammonium bromides in combination with magnesium ethoxide in alcoholic solution for stabilizing these media. In the present paper, the potential stabilising effect of another type of antioxidants - alkylimidazolium bromides - is compared to the one achieved using either an aqueous calcium or magnesium phytate treatment or a non-aqueous solution of tetrabutylammonium bromide in combination with magnesium ethoxide in ethanol. Two new antioxidants, 1-ethyl-3-methylimidazolium bromide and 1-butyl-2,3-dimethyl-imidazolium bromide, in combination with alkali magnesium ethoxide in ethanol, effectively stabilised iron gall ink containing model paper. The effect of stabilisation was superior to the previously studied antioxidants, i.e. tetraalkylammonium bromides and the two phytates. No negative side effects on the colour of the ink were observed, which makes the two antioxidants appealing alternatives to the currently used aqueous calcium phytate treatment. The study was extended also to the model papers containing corrosive copper pigments verdigris and malachite. The most effective treatment solution in this case was composed of tetrabutylammonium bromide and magnesium ethoxide in alcoholic solution. Although no negative side effects on paper containing iron gall ink or copper pigments were observed, it is imperative that the effects of the treatment solutions are studies also on a number of historical samples, before they are used for stabilisation of historical artefacts. © 2008 K. G. Saur Verlag 2008

Assessment of CpTi surface properties after nitrogen ion implantation with various dose and energy

Nitrogen ion implantation is one of the surface modification techniques used for increasing corrosion resistance of commercially pure titanium (CpTi). The nitrogen ion implanted CpTi in various doses markedly changes the corrosion resistance. Still the effect of nitrogen ion implantation on the CpTi at different energies needs to be verified. This study uses different methods to assess the CpTi surface properties after nitrogen ion implantation in various doses and energy. Surface hardness of the CpTi increases with an increase of the dose and decreases with an increase of the energy. The precipitation of the TiN increases with an increase of the nitrogen dose, and no formation of the Ti2N phase clearly appears. Corrosion resistance of the CpTi specimens can be upgraded to some extent after their surfaces are modified, implanting nitrogen ions at 100 keV by increasing dose. The optimum surface properties of the implanted CpTi are analyzed to contribute to materials science technology

Increased BDNF promoter methylation in the wernicke area of suicide subjects.

CONTEXT: Brain-derived neurotrophic factor (BDNF) plays a pivotal role in the pathophysiology of suicidal behavior and BDNF levels are decreased in the brain and plasma of suicide subjects. So far, the mechanisms leading to downregulation of BDNF expression are poorly understood. OBJECTIVES: To test the hypothesis that alterations of DNA methylation could be involved in the dysregulation of BDNF gene expression in the brain of suicide subjects. DESIGN: Three independent quantitative methylation techniques were performed on postmortem samples of brain tissue. BDNF messenger RNA levels were determined by quantitative real-time polymerase chain reaction. SETTING: Academic medical center. Patients or Other PARTICIPANTS: Forty-four suicide completers and 33 nonsuicide control subjects of white ethnicity. MAIN OUTCOME MEASURES: The DNA methylation degree at BDNF promoter IV and the genome-wide DNA methylation levels in the brain's Wernicke area. RESULTS: Postmortem brain samples from suicide subjects showed a statistically significant increase of DNA methylation at specific CpG sites in BDNF promoter/exon IV compared with nonsuicide control subjects (P < .001). Most of the CpG sites lying in the -300/+500 region, on both strands, had low or no methylation, with the exception of a few sites located near the transcriptional start site that had differential methylation, while genome-wide methylation levels were comparable among the subjects. The mean methylation degree at the 4 CpG sites analyzed by pyrosequencing was always less than 12.9% in the 33 nonsuicide control subjects, while in 13 of 44 suicide victims (30%), the mean methylation degree ranged between 13.1% and 34.2%. Higher methylation degree corresponded to lower BDNF messenger RNA levels. CONCLUSIONS: BDNF promoter/exon IV is frequently hypermethylated in the Wernicke area of the postmortem brain of suicide subjects irrespective of genome-wide methylation levels, indicating that a gene-specific increase in DNA methylation could cause or contribute to the downregulation of BDNF expression in suicide subjects. The reported data reveal a novel link between epigenetic alteration in the brain and suicidal behavior