New strategies to identify molecular markers predicting chemotherapy activity and toxicity in breast cancer

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Layered nano-TiO2 based treatments for the maintenance of natural stones in historical architecture

Layered treatments of natural stones based on dispersions of experimental nano-TiO2 and commercial TEOS, showing photocatalytic and self-cleaning properties have been set-up and tested. To enhance nano-TiO2 efficacy, a surface pre-treatment with tetraethyl orthosilicate has been proposed to avoid the penetration of NPs into the crystalline porous substrates and to improve their adhesion to the stone. Two treatment applications - wet-on-wet and wet-on-dry -have been compared, showing different results. A strong interaction Si-O-Ti has proved to be the key factor for the successful treatment, leaving the bandgap and relevant properties of nano-TiO2 unaltered. The layered treatments have been tested on a porous calcarenite (Noto stone) and a very compact marble (Carrara marble). The combined SiO2-nano-TiO2 treatments can find application in suitable cases where a surface consolidation is needed, ensuring a depolluting and self-cleaning durable activit

Improvements in marble protection by means of innovative photocatalytic nanocomposites

The application of photocatalytic and self-cleaning nanomaterials in the field of architectural heritage is an encouraging strategy for stone conservation and particularly for marble elements. In the present research, self‐cleaning nanocomposites were set-up by mixing water dispersions of TiO2 nanoparticles in commercial protective treatments based on organosiloxanes, fluoropolyethers and functionalized SiO2. The pure anatase phase nanoparticles used for their preparation are photoactive under solar light, in addition to UV radiation, due to their benzyl surface capping resulting in an increase of their efficiency in the degradation of pollutants. The nanomaterials applied on Carrara marble specimens show better performance in terms of surface colour compatibility and water repellency compared to traditional protective products. Actually, the introduction of nano‐TiO2 plays a role in the increase of the surface roughness, with a consequent reduction of the surface wettabilit

A general strategy for the synthesis of conjugated polymers based upon the palladium-catalysed cross-coupling of Grignard reagents with unsaturated halides

Palladium-catalysed cross-coupling between aromatic bisorganomagnesium reagents and aromatic dihalides has been experimentally evaluated as a general methodology for the synthesis of soluble conjugated polymers such as poly(p-phenylene)s 6 and 7, poly(p-terphenylenevinylene) 8, poly(phenylenethiophene) 9 and poly(phenylenepyridine) 10. Appropriate experimental conditions were first found in model reactions and then applied to the synthesis of polymers. Molecular mass values were determined both by GPC and by MALDI-TOF spectrometry. The latter technique also permitted accurate determination of the terminal groups of the polymeric chains. (C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002

Research of correlations between NDT and DT to assess mechanical properties of a soft stone in ancient masonry

A deep knowledge of the physical and mechanical properties of the constituent materials of ancient masonries is of crucial importance in the choice of the proper intervention technique. In case of historical buildings sustainable diagnostic procedures responding to the conservation constraints, should have the lowest degree of intrusion and the fullest respect for their physical integrity. The sample’s extraction from existing structures for laboratory tests is one of the major problems in the field of diagnosis of ancient buildings and this has moved the scientific community to propose alternative non-destructive techniques to evaluate the mechanical and physical properties of the building stones. In the present work non-destructive and destructive tests have been investigated as tools for assessing the compressive strength of “Lecce stone”, a soft calcarenitic stone used as traditional building materials in the Southern Italy. Ultrasonic pulse velocity (UPV), Schmidt hammer test and compressive tests on microcores have been compared with mechanical destructive tests on cubes in order to found correlations between the results. The final aim is to assess the reliability of the non-destructive investigated methods in describing the mechanical performance of the stone, reducing the use of destructive analyses on masonries

A non destructive testing method for masonry by using UPV and cross validation procedure

The paper presents a new procedure to assess the compressive strength of regular masonry starting from results of non-destructive ultrasonic pulse velocity tests (UPV) on the constituent materials. The procedure has been calibrated on a soft calcarenitic stone used in the heritage masonry of Southern Italy, and starts from the knowledge of the regression between UPV and the compressive strength (UCS) of the material, determined by means of a wide experimental campaign on different varieties of quarry samples. Through an improved cross validation technique, the proposed method allows to estimate the compressive strength of new samples by making only non-destructive measurements without the need to conduct compression tests. The quality of the procedure was assessed both at the block scale and at the wall scale by comparing the estimated results with those obtained experimentally. In particular, the experiments were performed using new quarry stone blocks and blocks taken from existing walls of two ancient buildings during restoration works. The proposed method has proven to be reliable for the investigated material and it is easy to apply also for other materials as soon as it is possible to carry out a preliminary calibration in the laboratory, which allows knowing the UPV–UCS relationship over a wide range of strengths

Ultrasonic pulse velocity for the evaluation of physical and mechanical properties of a highly porous building limestone

UPV as non-destructive technique can effectively contribute to the low invasive in situ analysis and diagnosis of masonry elements related to the conservation, rehabilitation and strengthening of the built heritage. The use of non-destructive and non-invasive techniques brings all the times many advantages in diagnostic activities on pre-existing buildings in terms of sustainability; moreover, it is a strong necessity with respect to the conservation constraints when dealing with the historical-architectural heritage. In this work laboratory experiments were carried out to investigate the effectiveness of ultrasonic pulse velocity (UPV) in evaluating physical and mechanical properties of Lecce stone, a soft and porous building limestone. UPV and selected physical-mechanical parameters such as density and uniaxial compressive strength (UCS) were determined. Factors such as anisotropy and water presence that induce variations on the ultrasonic velocity were also assessed. Correlations between the analysed parameters are presented and discussed. The presence of water greatly affected the values of the analysed parameters, leading to a decrease of UPV and to a strong reduction of the compressive strength. A discussion of the role of the water on these results is provided. Regression analysis showed a reliable linear correlation between UPV and compressive strength, which allows a reasonable estimation of the strength of Lecce stone by means of non-destructive testing methods such as the ultrasonic wave velocity. Low correlation between UPV and density was found, suggesting that other factors than density, related to the fabric and composition, also influence the response of the selected stone to the UPV. They have no influence on the UCS, that instead showed to be highly correlated with the packing density

Assessing the reliability of non-destructive and moderately invasive techniques for the evaluation of uniaxial compressive strength of stone masonry units

In this work Ultrasonic Pulse Velocity (UPV), Schmidt Hammer Rebound (SHR) test and strength assessment on microcores (UCSm) and standard cubic samples (UCSc) were used to detect the uniaxial compressive strength of stone masonry units. The analysis of the variability of the measurements allowed to investigate the significance of each test to differentiate the masonry blocks. The latter was evaluated by a Variability Index (VI), as the ratio between the variances at block scale and among the blocks. VI was found higher for UCSc and UPV than for UCSm and SHR measurements. A regression analysis aimed to the correlation of uniaxial compressive strengths evaluated by conventional destructive test on stone cubes with the other test results. The findings showed a good linear correlation among UCSc and UPV values (R2 = 0.83), thus supporting the reliability of UPV to screen the masonry units and to estimate their uniaxial compressive strength. The correlation of UCSc with UCSm was reasonable (R2 = 0.76), while it was low with SHR results; some limits related to the use of SHR and UCSm tests are also discussed

Synthesis of poly(aryleneethynylene)s bearing glucose units as substituents

A series of poly(aryleneethynylene)s functionalized with acetylated glucopyranosyl units were synthesized by the Pd-catalyzed reaction of trimethylsilylethynyl derivatives with aromatic halides in the presence of silver oxide