WPŁYW DODATKU NANOCZĄSTEK SIO2, TIO2 I AL2O3 NA WYBRANE PARAMETRY MIESZANKI BETONOWEJ I BETONU SAMOZAGĘSZCZAJĄCEGO SIĘ

The paper presents the results of own research on 10 series of self-compacting concrete which was modified with different amounts of SiO2, TiO2 and Al2O3 nanoparticle additives. The study included rheological properties of concrete mixes and mechanical properties of the hardened concrete in the form of compressive strength and bending strength. The obtained results are shown in relation to comparative concrete made without the addition of nanoparticles.W pracy przedstawiono rezultaty własnych badań 10 serii betonu samozagęszczającego się modyfikowanego różną ilością dodatku nanocząstek SiO2, TiO2 i Al2O3. Badaniami objęto cechy reologiczne mieszanek betonowych i cechy mechaniczne stwardniałego betonu w postaci wytrzymałości na ściskanie i zginanie. Uzyskane rezultaty przedstawiono na tle betonu porównawczego, wykonanego bez dodatku nanocząstek

Historical outline of iron mining and production in the area of present-day Poland

Funding Information: Funding: Funding from the European Institute of Innovation and Technology (EIT), a body of the European Union, under the Horizon 2020, the EU Framework Programme for Research and Innovation, through the MineHeritage Project (Grant Agreement 18111).The article presents the history of iron ore mining and production in present-day Poland and takes into account mining and production techniques and the influence of mining on the development of the surrounding areas. Examples of development are presented for the most important iron ore mining centers established since the period of the so-called Roman influences—Lower Silesia in the region of Tarchalice and the Świętokrzyskie region in the area of Góry Świętokrzyskie (Świętokrzyskie Mountains). The oldest traces of underground iron ore mining in Poland date back to the 7th–5th century B.C., and iron production dates back from the 1st century B.C. in the Częstochowa region where economically significant iron ore exploitation started in the 14th century and lasted until the 20th century. Studies showed that the development of iron ore mining in today’s Poland was associated with significant events in the country’s history, for example, with the expansion of a network of fortified castles in Silesia or with the industrial revolution. In each case, the increase in iron production resulted in the development and growth of the surrounding areas.publishersversionpublishe

Design of an innovative self-compacting material modified with recycled steel fibers and spent equilibrium catalyst for ultra-high performance applications

The main aim of the present study is to design an innovative self-compacting material modified with recycled steel fibers (RSF) from waste tires and spent equilibrium catalyst (Ecat) from the petrochemical industry for ultra-high performance application. For this purpose, 17 different mixtures were developed and analysed using different percentages of RSF (0%-3%) and replacement of cement by different percentages of Ecat (0%-15%). The developed mortars' self-compatibility was evaluated in a fresh stage using mini-cone tests. Regarding the hardened stage, the mortars were characterized at the ages of 7 days and 28 days using compression and unnotched flexural tests. The abilities of RSF to increase the post-cracking behavior of the specimens and to use Ecat to increase the bond performance between RSF and the cement matrix were assessed by performing notched three-point bending tests. The results of notched flexural tests were used to obtain the residual flexural strength in service limit state (SLS), ultimate limit state (ULS), and two equivalent flexural strengths. The experimental results for the fresh stage demonstrated that inclusion of RSF and Ecat significantly reduced the workability of mortars. The beneficial use of RSF and Ecat was observed to increase compressive strength and flexural strength for 7 days and 28 days of tested specimens. Notched flexural tested specimens showed that the addition of RSF and Ecat can significantly decrease the brittle behavior of cement-based materials by improving its toughness and post-cracking resistance. Middle-span deflection, crack initiation load, and ultimate flexural load were also increased with the addition of RSF and Ecat. In this sense, the results of this research showed that RSF and Ecat seem to have the potential to constitute a sustainable material for structural and nonstructural applications

Selected genetic factors increasing risk of neoplasia

Introduction: Neoplasia is defined as abnormal and excessive growth of selected tissue. Several factors, such as mutations in selected genes, can increase the risk of cancer expansion in human body. The aim of the article is to review the selected genetic factors which increase the risk of neoplasia and results of their presence in the human body. Material and methods: Articles in the Google Scholar, Pub Med database have been analysed using keywords: cancer, neoplasia, genetic factors, driver genes, cancer transformation, older people. Results: The aim of several genes is repairing damaged or dysfunctional DNA and preventing cells from abnormal or excessive. Mutations in selected genes cause inhibited production of the gene protein product or a change in its function, which increase the risk of neoplasia. The presence of mutated genes results in the initiation of the process leading to expansion of cancer cells in selected tissue. Moreover, a genetic mutation can lead to syndrome of tumors occurring in several organs. However, the increasement of cancer risk is related to numerous mutations, whereas the minority of carcinomas occur because of congenital gene defect and the majority is caused by environmental factors which contribute to creating various mutations. Conclusions: Thanks to the development of genetics in the field of medicine and introduction of genetic tests, the process of diagnosis of several tumors and syndromes is more efficient than in the past. The occurrence of mutation in genes, such as BRCA1, BRCA2, VHL, MSH2 and MLH1 and many more, relates to presence of selected tumors. By the introduction of pharmacogenetics, dozens of molecular-targeted drugs are used in the treatment of several types of cancers leading the achievement of therapeutic success. Nevertheless, the genetic background of many types of cancers is unknown and needs further study, as well as drugs targeting at selected genes mutations requires more development and guidelines in the treatment process. Keywords: cancer; neoplasia; genetic factors; driver genes; cancer transformation; older people

Using digitalization for knowledge transfer in society is the future of transplantation: A pilot study

Introduction: Recently, knowledge about transplantation among the general public has diminished. The COVID-19 pandemic has worsened this transplantation-related crisis, but has simultaneously contributed to the greater development of online education. The aim of the study was the assessment of the level of general public knowledge regarding transplantation and suggesting new possibilities of utilizing digital forms of information transfer in the process of societal transplant education (STE).Material and methods: An online survey questionnaire, containing questions related to common transplantation knowledge, was conducted among students of faculties of medicine.Results: Nearly the entire study group indicated that increasing knowledge as regards organ transplantation may prove to have a significant impact with respect to donating organs after death for transplantation. The study revealed that over 60% of respondents held a false belief that a declaration of intent was a legally binding document rather than only a declaration of will. Over 20% of respondents erroneously believed that the donor’s family had the right to object to organ procurement for transplantation. Facebook, websites for patients and applications were indicated as effective forms of STE. Having obtained the results, the first Polish prototype of an “e-transplant” application was designed for thepurposes of STE.Conclusions: The level of knowledge concerning organ donation for transplantation is insufficient among the general public and necessitates the development of modern STE methods. All forms of information transfer in the virtual media space become particularly useful for the purposes of STE, including the created application

Reversal ventilation as a method of fire hazard mitigation in the mines

Reversal ventilation is one of prevention methods against fire hazard in underground mines, but it is not recommended for the mines where methane is present. The authors introduce the new method of reversal and by conducting numerical simulations they prove that it allows to keep methane at the acceptable level during miners escape. However, it requires connection between the subnetworks of the main ventilation fans. It was also shown, that by using the method some escape routes will be shortened. It is possible to apply this method in the mines where the fans and stoppings are fully controlled across the full range of their operating parameters. The findings are important for underground mines, as well as for surface facilities where air control or smoke control is managed by two or more fans.Web of Science137art. no. 175

The impact of artificial sweeteners on the risk and course of large intestinal adenocarcinoma in the elderly

There are many confirmed risk factors for development of the colorectal cancer, which is one of the most common malignant tumor among both females and males. Moreover, it is a cause of significant percentage of all cancer-related deaths. Even with treatment, the 5-year survival rate is very low. We concentrate on impact of artificial sweeteners on risk and course of adenocarcinoma of colon

Effect of combined action of doxorubicin and calcifediol on MCF-7 breast cancer cells

Introduction: Breast cancer is one of the most common cancers in women. Current recommendations for combination therapy in patients with breast cancer are still being developed and new therapies with greater success are sought. A relatively new approach is the administration of cytostatics in combination with vitamins. Hence, the study aimed to clarify whether the combination of calcifediol [25(OH)D3] with doxorubicin affects the response of the MCF-7 breast cancer cell line to the cytostatic. Material and methods: In the MCF-7 cell line, the authors assessed cytotoxicity using the MTT assay, analysed the cell cycle and cell death mechanism using flow cytometry, and examined the structure of the cytoskeleton and cell morphology. Results: The results showed that doxorubicin in combination with calcifediol in a 1:1 ratio showed a synergistic effect resulting in a dose-dependent decrease in cell survival. Further studies have shown that this is due to the pro-apoptotic and necrotic effects of the combination of these compounds. There were also changes in the organization of the cytoskeleton and cell morphology. In addition, features of entosis were noted in MCF-7 cells. Conclusion: The synergistic effect of doxorubicin and calcifediol significantly reduced the viability of MCF-7 breast cancer cells. Inducing the desired effect by lowering the cytostatic dose is of great clinical importance, taking into account the cardiotoxicity of doxorubicin. Another very interesting aspect is the entosis process induced in the present research, which may have a dual nature

Influence of the auxiliary air-duct outlet and the brattice location on the methane hazard-numerical simulations

The article presents the results of research into the influence of the location of auxiliary ventilation devices on the distribution of methane concentrations at the outlet of the longwall in an underground mine. Since this area is crucial from the point of view of explosion risk, the existence of an optimal arrangement of these devices could lead to improved safety of the crew working in the area. The aim of conducted study was to examine if the impact of this devices placement is significant. The research was carried out with the use of computational fluid dynamics (CFD) modeling-Ansys Fluent. The analyses took into account the location of the two most commonly used devices: a brattice and an auxiliary air-duct. The numerical model has been prepared and validated based on in situ measurements. Thirty-two cases of device configurations were analysed. The length and position of the brattice, as well as the height and position air-duct outlet along tailgate, were modified. It has been shown that although the presented solutions are an effective risk mitigation method, contrary to the common opinion of many practitioners, the impact of their exact placement, provided it is compliant with the regulations, is not significant for the registered methane concentration distribution at a longwall outlet.Web of Science1510art. no. 367