Wrocław University of Technology

About: Wrocław University of Technology is a education organization based out in Wrocław, Poland. It is known for research contribution in the topics: Laser & Computer science. The organization has 13115 authors who have published 31279 publications receiving 338694 citations.

Comparision of the cytotoxic effects of birch bark extract, betulin and betulinic acid towards human gastric carcinoma and pancreatic carcinoma drug-sensitive and drug-resistant cell lines

Abstract: Betulin and betulinic acid are naturally occurring pentacyclic triterpenes showing cytotoxicity towards a number of cancer cell lines. These compounds can be found in the bark of the many plants. In this report we have compared the cytotoxic activity of crude birch bark extract and purified betulin and betulinic acid towards human gastric carcinoma (EPG85-257) and human pancreatic carcinoma (EPP85-181) drug-sensitive and drug-resistant (daunorubicin and mitoxantrone) cell lines. Our results show significant differences in sensitivity between cell lines depending on the compound used, and suggest that both betulin and betulinic acid can be considered as a promising leads in the treatment of cancer.

Shear strengthening of reinforced concrete beams with PBO-FRCM composites

Abstract: The work analyses the functioning of reinforced concrete beams which are shear reinforced with FRCM (Fibre Reinforced Cementitious Matrix) composite mesh on mineral mortar. The analysis of previous tests provides an overview on the efficiency of the related FRP (Fibre Reinforced Polymers) system used for strengthening the beams against shearing forces. The information gathered on the functioning of FRCM strengthened concrete elements show that the key factor in this technology is ensuring appropriate carrying capacity of anchoring of the mesh. The tests were carried out on reinforced concrete beams with different design of lateral reinforcement. The beams differed in terms of the angle of inclination of the reinforcement to the longitudinal axis, as well as in terms of the manner of anchoring the mesh at the top and bottom surface of beams. The destruction mechanisms of beams were analysed and described. Value of deflection measured at the maximum load for all of the beams is significantly greater than the allowable value. The distribution of strains is presented as a function of the load, where the phases of operation in relation to shear of FRCM reinforced beams are visible.

Energy-Efficient Size Approximation of Radio Networks with No Collision Detection

Abstract: Algorithms for radio networks are studied in two scenarios: (a) the number of active stations is known (or approximately known) (b) the number of active stations is unknown. In the second (more realistic) case it is much harder to design efficient algorithms. For this reason, we design an efficient randomized algorithm for a single-hop radio network that approximately counts the number of its active stations. With probability higher than 1 - 1/n, this approximation is within a constant factor, the algorithm runs in poly-logarithmic time and its energy cost is o(log log n). This improves the previous O(log n) bound for energy. In particular, our algorithm can be applied to improve energy cost of known leader election and initialization protocols (without loss of time efficiency).

A Family of Microporous Materials Formed by Sn(IV) Phosphonate Nanoparticles

Abstract: Reaction of Sn(IV) with phosphonic acids results in the formation of tin phosphonates with a spherical morphology arising from the aggregation of nanosized individual particles. Under high magnification, the spheres are shown to be porous with surface areas of 200-515 m2/g, depending on the type of phosphonic acid and the synthesis conditions used. The pores are largely micro in nature but also somewhat dependent on the type of phosphonic acid utilized in the preparation. Both aliphatic and aromatic organic phosphonates form these spherical aggregates. Functional groups, such as amino and carboxyl, may be introduced as part of the phosphonic acid or subsequently by further reaction, leading to a large family of naturally formed nanoparticles with accompanying microporosity.