Effect of SO2 Dry Deposition on Porous Dolomitic Limestones

The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain) used as building material in stone monuments and submitted to artificial ageing by SO₂ dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexan-N, Silres BS 290 and Tegosivin HL 100) and a newly synthesized hybrid nanocomposite with silsesquioxane units (TMSPMA) were used. A comparative assessment of the data obtained in this study underlines that a better limestone protection was obtained when treated with the hybrid nanocomposite with silsesquioxane units.     

Diabetic retinopathy complications--12-year retrospective study

It is analyzed, on a retrospective study on 12 years, the incidence of diabetus melitus cases, hospitalized in the Ophthalmologic Clinic from Craiova with special mention to the frequency of the diabetic retinopathy, of it's complications and in an accordance to other general diseases, especially cardiovascular's, which contributes to the aggravation of the diabetic ocular in juries evolution. The study underlines the high incidence of the new founded cases with diabetus melitus in complicated diabetes retinopathy stage; the high frequency of ocular complications is explained, according to our statistic facts and through an insufficient treatment, sometimes incorrect and many other cases total neglected by the patients.     

Gemische von polymeren durch cofällung,III. Mitt. Untersuchung der binären polymersysteme: Polyacrylnitril/acetylcellulose,polyvinylacetat/acetylcellulose und polyvinylacetat/polyacrylnitril

The variation of the activation energy of the thermal degradation of polymer mixtures with their composition leads to valuable indices concerning the compatibility or incompatibility of the homopolymers. By this method it is possible to accentuate small deviations of the activation energy from the additivity and to delimit the interval of maximum compatibility. Also it is possible to predict if the formed pseudosolutions will be more or less thermostable than the corresponding homopolymers. During the mixing of pseudocompatible polymers generally two opposite tendencies can be observed: (a) an increase of activation energy by the formation of associates and therefore an increase of thermostability, and (b) a decrease of activation energy by the formation of solid solutions with eutecticum, which are less thermostable than the initial homopolymers. Thus, the cellulose acetate/polyacrylonitrile coprecipitation polymers show negative deviations of the activation energy, with a minimum of ΔE = ?14,8 kcal/mole for the eutecticum. This coprecipitation polymer decomposes 25°C lower than the corresponding homopolymers. The polyacrylonitrile/poly(vinyl acetate) coprecipitation polymer on the other hand shows positive deviations of the activation energy with a maximum of ΔE = 12,3 kcal/mole for the 1:1 mixture. The corresponding initial decomposition temperature rises about 15°C. The activation energy of the cellulose acetate/poly(vinyl acetate) mixtures obeys the additivity; these polymers are not compatible.     

Modification of the peritoneoscopic technique of peritoneal dialysis catheter insertion: experience of an interventional nephrology program

Bowel perforation is a well-recognized complication of peritoneal dialysis catheter insertion and is associated with increased morbidity and cost of medical care. In this article we describe our 2-year experience (August 2001-October 2003) with a modified peritoneoscopic technique of peritoneal dialysis catheter insertion to minimize the incidence of bowel perforation. Seventy patients underwent 82 consecutive peritoneal dialysis catheter insertions using the innovative technique. The modified technique is very similar to the traditional peritoneoscopic procedure except for the following differences. To gain access to the peritoneal cavity, a Veress insufflation needle (Ethicon Endo-Surgery Inc., Cincinnati, OH) is utilized instead of the trocar. In contrast to the sharp tip of the trocar, the Veress needle has a blunt, self-retracting end. In addition, the Veress needle is only 14 gauge as opposed to the 2.2 mm diameter of the trocar. Upon introduction of the Veress needle into the abdominal cavity, two "pops" are discerned similar to the trocar. After introduction, 400-500 cc of air are infused and the needle is removed. The infusion of air creates a space between the peritoneal surface of the anterior abdominal wall and the bowel loops. At this point, the cannula with trocar is inserted into the space created. The rest of the steps of the procedure are the same as the traditional peritoneoscopic technique. Utilizing the innovative technique, all 82 catheter insertions were performed successfully without a single bowel perforation. No other complications except for catheter migration (n = 2) were noted. The extra cost of the needle (35 USD) should be viewed in the context of the costs associated with management of a bowel perforation. Large-scale studies are needed to confirm the superiority of this innovative technique over the traditional peritoneoscopic insertion found in our case series. In the interim, however, the increased morbidity and cost associated with bowel perforation calls for logical measures to be taken to avoid this dreaded complication.     

Retinophotography--screening method in diabetic retinopathy

The paper presents the modern screening method for diabetic retinopathy-the retino-photography. We present our experience on this issue, regarding the patients with diabetic retinopathy screened in Diabetic Eye Department, Ophthalmology Clinic Craiova, between October 2002-June 2005.     

Cellular immunophenotypes in human embryonic, fetal and adult heart

The cellular immunoprofile of cardiac dysfunctions and lesions of ischemic etiology are insufficiently studied to date, especially regarding the contribution of non-cardiomyocytic structures. Aiming to explore this immunoprofile, we used immunohistochemistry applied on embryonic, fetal and adult normal or ischemic myocardium. We observed a decrease of smooth muscle alpha-actin expression in fetal vs. embryonic cardiomyocytes, its absence in normal adult myocardium and its intense expression in the fibrotic scars of ischemic myocardium. DDR2 and vimentin, which are present in the interstitial cells and cardiomyocytes of the embryo, fetus and normal adult heart, are absent in the fibrotic scar tissue and cicatricial infarction, the latter expressing smooth muscle alpha-actin and CD34. This suggested that myofibroblasts and not local fibroblasts that participate in ischemic remodeling. An EGFR-positive vascular network was better represented in the ischemic heart than in the adult normal one, a fact possibly related to EGFR implication in cardiac ischemic pre- and post-conditioning. Therefore, cardiomyocytes and non-cardiomyocytic cells have an undulating immunoprofile according to the intrauterine life stage or age after birth, and a variable contribution in cardiac lesions, mostly in ischemic ones.     

Optimization of Wire Arc Additive Manufacturing (WAAM) Process for the Production of Mechanical Components Using a CNC Machine

The paper presents a CNC component manufacturing process using the WAAM process. The study depicts all the execution steps of a component from the CAD drawing, deposition procedure (technological parameters, times, layers, etc.), examination, and economic calculation. The manufacturing of this component using WAAM is more advantageous given the fact that the execution time and delivery are significantly shorter, mainly when a single piece is required and also when discussing the raw material used, usually expensive titanium alloys. For example, for Ti-6AI-V used in the aircraft industry, for which the material price is about 90 Euro/kg, the costs for obtaining a given component using the WAAM process will be about 497 Euro/piece compared to 1657 Euro/piece when using another manufacturing process, as it is shown in this paper. In conclusion, additive manufacturing can easily become a feasible solution for several industrial applications when it replaces a classic manufacturing process of a single component or replacement products, even simple-shaped.