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In this work, for the first time, a material was prepared that releases the drug in a controlled manner under the influence of the pH of cancer environment. The material is zinc zeolite, which only releases the drug at an acidic pH. The release of the drug in an acidic environment indicates a very high potential of the synthesized material in the treatment of cancer. This material does not release the drug at pH 7.4 even for more than 100 h which proves that healthy organs will not be affected. The advantage of this material over those previously described in the literature is that it releases the drug very quickly under the influence of the cancerous environment (88% of the drug during approx 2 h), as well as the fact that it does not release the drug in a different environment. Materials with both features have not been previously described, there are only works on materials having one of these features. Moreover, this material releases zinc ions which additionally act on cancer cells by inducing apoptosis of cancer cells by increasing the intracellular production of reactive oxygen species.

Insufficient mechanical properties of hydroxyapatite-based composites prompted the search for new and effective solutions for dental applications. To improve the mechanical properties without losing the remineralization potential, the use of hybrid fillers was proposed. The first of them was based on the formation of hydroxyapatite (HA) layer on the surface of SYLOID®244 silica. The second of the investigated fillers was created by simultaneous synthesis of nanoparticles from precursors of HA and silica. The obtained fillers were extensively characterized by spectral methods including X-ray Diffractometry (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), and X-ray fluorescence (XRF), as well as by Scanning Electron Microscopy (SEM)/Energy Dispersive Spectroscopy (EDS). Tests using probiotic microorganisms were an important part of the analysis, indicating that there was no potential interaction of the materials with microflora. The tests of degree of conversion, depth of cure, opacity, sorption, solubility, flexural and compressive strength, and the remineralizing potential also showed that the composites with nano-sized silica/HA showed better mechanical properties than the composites with HA alone or commercial silica and at the same time the remineralization remained at the desired level. Thus, the proposed composite has a high application potential in the creation of implants and dental materials. Graphical abstract

Bisphosphonates are drugs that are used to treat osteoporosis that causes the low mineral density of the bones. These drugs can be delivered in several ways, but each method has disadvantages. Materials with high potential as carriers of these drugs are zeolites with divalent ions. The aim of this study was to investigate the effect of divalent cations (calcium, magnesium, zinc) and drug type (risedronate, zoledronate) on sorption and release of the drug for osteoporosis. It was proved that drug sorption occurs on all zeolites presented in this work. Risedronate sorption was highest in zinc zeolite and lowest in calcium zeolite. In the case of zoledronate, sorption was most effective in magnesium zeolite and the least effective in zinc zeolite. Very large differences in drug release profiles were also observed. Risedronate was released several times longer than zoledronate. The diversity of the results indicates that the examined materials can be used in different types of drug delivery systems. They can be used, for example, intravenously or in the form of implants due to the different release profiles. Furthermore, the proposed carriers also release magnesium and calcium ions which are used in the prevention of osteoporosis, and zinc ions which have antibacterial properties.

This article presents different types of commercially available roof waterproofing membrane systems used on roofs with large surface area. It deals with the causes of deterioration of such membranes due to environmental factors and describes the tests used to detect leaks and determination of the severity of deterioration of polymeric membranes taking into account the properties declared by their manufactures. The last part of the article is a case study comparing a brand new membrane with a membrane after 27 years in service.

Chitosan scaffolds are a potential material in many biomedical applications. A particularly interesting application is their use in bone tissue engineering. Because of their biocompatibility and nontoxicity, they are an ideal material for this application. What is missing from chitosan scaffolds is controlled drug release. They can obtain this property by adding drug carriers. In this work, chitosan‑calcium zeolite scaffolds were prepared and used in the controlled release of the drug for osteoporosis - risedronate. Their properties have been compared with those of the popular chitosan-hydroxyapatite scaffold. The zeolite was evenly distributed throughout the scaffold. More drug was retained on the scaffold with the addition of zeolite compared to that with the hydroxyapatite. The new scaffolds have proven to be able to retain the drug and slowly release it in small doses. The results obtained are promising and show great potential for this material in bone tissue engineering.

During the fire, structures of a building are exposed to the effect of a high temperature. As a result, the strength parameters and physical properties of concretes and cement mortars undergo change. Their range depends on the time and temperature of the fire. Describing the changes of the internal structure of concretes and mortars resulting from a fire is important in the fire diagnostics of the structures. The paper presents the results of an original research project, within which there was an attempt to relate changes in mechanical properties of the cement mortars with changes in the crystal structure of cement paste. For this purpose, the authors prepared cement prisms, which were heated at various temperatures that occur during a fire after 28 days of their curing. Then, the samples were subjected to compressive strength tests and tests of a structure and a phase composition using an electron scanning microscope. Scanning microscopy is a precious research method that allows observing surfaces of various materials with magnifications from x50 to even x1000000 at a very big sharpness depth. The tests conducted by the authors showed that the effect of fire and of the gradient of high temperatures on the executed samples causes the deterioration of the cement paste in the form of changes in physico-mechanical properties and in its internal structure. As the temperature increases, the compressive strength of the paste decreases gradually and proportionally. The SEM analysis also showed that the change in the physical parameters of the cement paste is reflected in its phase composition.

Nowadays, on the construction market, there are offered agents for concrete hydrophobization. In most cases, these are preparations that are applied on surfaces of already existing elements. The main disadvantage of such agents are strictly specified conditions, under which they can be applied. It is not recommended to apply the preparations for the elements under water level, exposed to contact with water under pressure, and with visible cracks and scratches [1, 2]. The article presents the results of tests of an innovative agent for concrete hydrophobization that has not disadvantages of the currently applied materials – application of the developed solution takes place at the stage of creating concrete mix. The preparation may be classified as an admixture for concretes.

Commonly used waterproofing membranes consist, in over 80%, of bituminous blend. That is why thorough knowledge of factors having impact on the destruction of waterproofing products is of utmost importance. In many cases it is caused by rheological changes, especially ageing processes occurring in bitumen. The purpose of the research is to develop modern solutions that will slow down the processes which occur and thus will extend the life of waterproofing materials. The paper discusses factors affecting the intensity of bitumen ageing and describes physicochemical changes caused by ageing. It also presents test results of bitumen modified with imidazoline which can be used as inhibitors of ageing processes.

The basic feature characterising the concrete’s quality and its usefulness for a structure is compressive strength. However, other features, such as frost resistance, absorbability, tightness, abrasiveness, decide on the durability of concrete in the structure as well. The paper presents the results of tests conducted on an ecological air entraining agent applied as a concrete mix admixture. The air entrainment of a concrete mix is aimed at entraining additional air pores with appropriate shape, size, and distribution into the concrete structure. The air entrainment is one of the main technological processes aimed at improving the concrete’s resistance to destructive effect of frost [1,2,3,4].

The paper assesses the influence of two types of modifiers obtained from natural resources on the properties of road asphalt and asphalt mix containing reclaimed asphalt pavement (RAP). In this research, rapeseed and oleic imidazolines were used as modifiers. Based on the penetration, softening point and dynamic viscosity tests, 2% addition of imidazoline was determined as optimal. It was found that imidazolines can be applied as a rejuvenator for asphalt mix with RAP due to their softening effect of the aged binder. Asphalt mix with imidazoline modifier and polymer-modified bitumen is characterized by improved resistance to low-temperature cracks and permanent deformations.

In spite of strong competition of synthetic materials (including PVC, EPDM), bitumen remains the major component of most waterproofing materials. It makes up approx. 80% by weight of the final product. The characteristics of bitumen mix have a decisive impact on the quality of the final product. During storage, transport, manufacturing and installation of waterproofing materials, bitumen is subject to ageing. As a result of the ageing process the characteristics of bitumen waterproofing materials deteriorate, roofing membrane becomes more rigid and cracks. The damaged waterproofing layer ceases to perform its function; it does not protect the building envelopes against water penetration. The development of organic chemistry allowed the synthesis of a number of modifying substances used for chemical modification of bitumen. Among the most promising are heterocyclic organic compounds belonging to the group of imidazolines. The article presents the results of preliminary laboratory tests of bitumen modified jointly by SBS and imidazoline. The objective of the study was to find a new type of bitumen modifier (hybrid modifier) synergically combining the advantages of both types of presented modifications.

As climate changes progress we are dealing with violent and excessive environmental actions. However, the impacts of loads acting on a building object caused by unlikely phenomena such as: fire, explosion, flood, vehicle impact, plane impact, excessive snowfall, and excess wind gusts are still being ignored when analyzing the structure of building objects in the combinatorics of loads. The paper presents a multi-criteria approach to accidental actions and analyzes design situations and load combinations in relation to accidental actions. The existing legal acts were used to define the concept of a construction disaster. The authors verified, on the basis of applicable legal acts and design guidelines, individual analysis strategies for ensuring the safety of building objects and divided them into consequence classes of structural damage. They collected and analyzed the number of construction disasters which occurred in Poland between 1995&ndash, 2019 (25 years) based on the data from the General Office of Building Control. The number of disasters was divided by voivodeships and causes and supplemented with the data on the number of people injured. The article presents the direction of research development that could be undertaken in order to eliminate future catastrophes caused by the omission of the analysis of the impact of accidental actions at the design stage. Statistical analyses were carried out to show whether land use, population density, and weather factors (wind) affect the number of recorded disasters. It has been shown that regions that have preserved the sustainable development of their territories are less vulnerable to disasters resulting from extreme weather events.

The article deals with the issue of determination of the content of SBS (Styrene-Butadiene-Styrene) in polymer-modified bitumens (PMBs). The effect of SBS copolymer on the physical and rheological properties of bitumens has been thoroughly investigated and widely described in the literature. Condition surveys of structures and evaluation of the properties of materials used at construction sites have become a huge challenge for construction engineering. Determination of the content of SBS modifier in various building materials (asphalt mixtures and bituminous waterproofing compounds) is a good example in this respect. Based on the laboratory tests, mid-infrared spectroscopy was found to be the most effective analytical method. It can be used for easy detection of the presence of SBS in a modified bitumen. However, quantitative analysis is an issue that calls for research. Currently, there are no standard guidelines, whether national or European, that would regulate the method of testing. Three test methods were assessed in this study: the AASHTO T302&ndash, 15 standard method and two Australian methods described in codes of practice (T521 and Q350) developed by the local authorities, which define a standard way of determining the amount of SBS in polymer-modified bitumens. The tests were carried out on standard controls and samples sourced from the industry. The above-mentioned test methods were assessed in terms of accuracy of determination, reliability of results obtained on the industrial samples, level of complexity of the test procedure, sample preparation techniques and the type of the required reagents.

Various additives, admixtures and modifiers are used to improve technical properties and strength characteristics of building materials. Manufacturers of waterproofing materials, concrete, ceramics and bitumen have to use innovative, increasingly complex and costly additives, admixtures or modifiers. As a result, simple and inexpensive substances have been replaced by complex, long chain polymers, multi component resins or plastics. For economic and ecological reasons waste materials are more frequently used as additives, admixtures and modifiers. Nowadays the most commonly used physical modifiers of bitumen belong to the group of polymers - large molecular organic compounds of natural origin or being the result of planned chemical synthesis. Polymers are substances that do not chemically react with bitumen, they act as fillers or create a spatial network within bitumen (the so called physical cross-linking). The development of organic chemistry has allowed the synthesis of a number of substances chemically modifying bitumen. The most promising are heterocyclic organic compounds belonging to the group of imidazolines. The aim of the study presented in this paper was to demonstrate the suitability of processed natural and post-refining fat waste (diamidoamine dehydrate) as bitumen modifier. This paper discusses the impact of adding technical imidazoline on selected bitumen characteristics. Samples of bitumen 160/220, which is most commonly used for the production of waterproofing products, were analysed. For base bitumen and bitumen modified with technical imidazoline the following measurements were taken: measurement of the softening point by Ball and Ring method, determination of the breaking point by Fraass method and needle penetration measurement at 25°C. Later the samples were aged using TFOT laboratory method and the basic characteristics were determined again. The results showed that a small amount of imidazoline improved bitumen thermoplastic parameters at low temperatures and had a significant impact on weakening bitumen oxidation and ageing. The addition of technical imidazoline prevents bitumen from hardening, thus increasing its flexibility and its resistance to mechanical damage. Due to many difficulties in the production of polymer bitumens and in order to find cheaper, more environment friendly solutions, the authors proposed an ecological bituminous modifier which, due to chemical reaction with binders, creates a stable and firm in time product. Imidazolines have a negative impact on bitumen softening point, which makes them impossible to use as an independent modifier. Therefore, at a later stage of the research, the authors will attempt to create a hybrid bitumen modifier which will combine the beneficial effect of polymers and imidazoline on the characteristics of bituminous binders.

Asphalt is one of the most commonly used building material. The first attempts at modifying asphalt were made at the beginning of the twentieth century. Nowadays the most popular asphalt modifier is the styrene-butadiene-styrene (SBS). This thermoplastic elastomer increases the thermal resistance of bitumen, widens the range of plasticity and amends rheological properties. IR spectroscopy is by far the most common instrumental method used in analytical chemistry. The popularity of this method results from its simple measurement technique, universality and high precision. That is why IR spectroscopy applies to the analysis of polymer modified binder (PMB) used in waterproofing.