Contemporary Materials最新文献

{"title":"APPLICATIONS OF BIOMATERIALS IN REGENERATIVE MEDICINE AND TISSUE ENGINEERING – CONCEPTS AND PERSPECTIVE","authors":"S. Najman, S. Stojanović, J. Živković, J. Najdanović, M. Radenković, P. Vasiljević, Nenad L. Ignjatović","doi":"10.7251/comen2301001n","DOIUrl":"https://doi.org/10.7251/comen2301001n","url":null,"abstract":"Regenerative medicine (RM) exploits the innate potential of the human body to effectively repair and regenerate damaged tissues and organs with the help of various biomaterials. Tissue engineering (TE) makes it possible to replace damaged tissues and organs with new ones. Research in the field of biomaterials has significantly improved the area of RM and TE. Biomaterials are used as orthopedic, dental, cardiovascular implants, medical devices, in the fields of reconstructive and regenerative medicine, among others. Important preconditions for the biomaterial to be used for implantation are its biocompatibility and biofunctionality. Biomaterials should enable adhesion, migration, proliferation and differentiation of cells. The biological properties of biomaterials are a reflection of their physicochemical properties, such as internal architecture, surface characteristics and charge. Biomaterials used in tissue regeneration should mimic the natural structure of the extracellular matrix and represent a physiological microenvironment for normal cellular functions. These biomaterials should also have adequate biodegradability properties to facilitate the formation and growth of new tissue. Biomaterials for use in RM can be of natural or synthetic origin, polymers by structural properties, ceramic and composite type, and based on bioreactivity they can be bioinert or bioactive. In RM and TE, polymers of different classes, natural and synthetic, are used, which can be made as intelligent materials. The structure of hydrogels in the form of a porous network represents a good matrix for cell activity. Ceramic biomaterials based on hydroxyapatite (HAp) are selected for use in RM and TE, especially solid tissues. Properties, such as composition, particle size, material shape, porosity, surface charge, topography, etc., are relevant for the proper use of HAp materials. The properties of HAp allow modification of its structure, surface, particle size design at the micro and nano level, hybridization with polymers, metals, etc. which is very important for its applications. Designed micro-nanohybrid HAp structure is most similar to the bone structure, making the cell environment closest to natural. Bone tissue engineering (BTE) is based on the combined use of cells, osteostimulating (osteoinductive) factors and biomaterials as a scaffolds and carriers for bone regeneration and defects repair. In BTE adipose-derived mesenchymal stem cells (ADSCs) are often used that are induced in vitro towards osteogenic cells or endothelial cells, and freshly isolated stromal vascular fraction can also be used. Blood components (PRP, blood plasma or blood clot) can be included in the composition of the BTE construct as a source of osteoinductive factors. In vitro models and methods were used to examine the biocompatibility, immunomodulatory and regenerative potential of biomaterials, as well as their influence on cellular functions. After in vitro methods, and before clinical ","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85113118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PHOTODIELECTRIC CHARACTERIZATION OF LIGHT-DRIVEN Au/TiO2 NANOMOTORS IN LIQUID MEDIUM","authors":"Danijela Danilović, Đ. Trpkov, R. Dojčilović, Dragan Tošić, Jelena Pajović, B. Škipina, D. Dudić","doi":"10.7251/comen2301025d","DOIUrl":"https://doi.org/10.7251/comen2301025d","url":null,"abstract":"This article reports on photodielectric properties of hydrocolloids of TiO2 particles and Au/TiO2 hybrid particles of lateral dimension of ∼200 nm. Illumination of the colloids with visible light did not cause measurable changes in their electrical conductivity, while the application of UV (365 nm) light led to photoinduced increase in conductivity of up to 2%. The photogeneration of ions in water, regardless of the presence of the particles, makes a dominant contribution to the photoinduced increase in conductivity of the colloids.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82226793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LABORATORY TESTING OF UNSTIMULATED AND STIMULATED SALIVA BUFFERING CAPACITY IN PATIENT AND CONTROL GROUPS AFTER TITRATION WITH HCl AND NaOH","authors":"R. Arbutina, N. Trtić, O. Janković, V. Veselinović, Irena Radman Kuzmanović, V. Mirjanić, Sanja Gnjato, Adriana Arbutina","doi":"10.7251/comen2301079a","DOIUrl":"https://doi.org/10.7251/comen2301079a","url":null,"abstract":"Introduction: Buffer capacity is the “resistance” of saliva to change pH when treated with acid or base. In other words, saliva has a greater buffering capacity to which more acid or base needs to be added in order for its pH to decrease or increase by a certain value. Aim: Laboratory examination of the buffering capacity of unstimulated and stimulated saliva in patients of the experimental group and subjects of the control group in relation to age and gender. Material and method: Determination of the pH value of saliva is done with a pH meter (HANNA instruments 8521). The obtained amount of saliva is diluted with distilled water. Each sample is divided into two equal parts, and the pH value of the sample is measured. Saliva titration is done with acid (HCl) and base (NaOH), adding 100μl of HCl to each sample and 100μl of NaOH to each sample, in the range from pH 3 to pH 11. Results: There is no statistical significance of the differences in the mean values of the buffer capacity. Conclusion: There is a difference in the mean values of the buffer capacity in favor of men, which explains that in men a larger amount of spent buffer is needed to change the pH by one unit.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74716997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"INVESTIGATION OF STRUCTURAL CHARACTERISTICS ON FERRITIC NODULAR CAST IRON","authors":"D. Ješić, B. Savković, P. Kovac, B. Strbac, D. Sarjanović","doi":"10.7251/comen2301071j","DOIUrl":"https://doi.org/10.7251/comen2301071j","url":null,"abstract":"The linear form of graphite in gray cast iron is not favorable due to the weakening of the metal base and strong sources of stress concentration at the ends of the lamellae. Converting the lamellar form of graphite into nodular form is done by adding modifiers and pre-secreting smaller amounts of magnesium or cerium. In this way, the stress concentration due to graphite inclusions in nodular cast iron is significantly lower than in gray cast iron. “Nodular cast iron is a foundry pseudobinary alloy of iron and carbon, which was mostly excreted in the form of spherical graphite”. Depending on the structure of the metal base, the properties of strength and plasticity also depend, but certainly the shape, size and arrangement of graphite nodules has a significant influence. For these reasons, the size of graphite nodules is also determined, the highest values of the average nodule being from 50 to 10 μm. In this paper, a researched nodular cast iron with a ferrite structural base is given. The mentioned nodular casting was isothermally improved and tribologically tested, on a “pin and disc” tribometer. The obtained results are presented tabularly and diagrammatically.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"15 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85749409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"INFLUENCE OF GEOLOGICAL PARAMETERS ON THE INDOOR RADON CONCENTRATION IN THE CITY OF TREBINJE","authors":"Z. Curguz, N. Đurić","doi":"10.7251/comen2301064c","DOIUrl":"https://doi.org/10.7251/comen2301064c","url":null,"abstract":"The paper deals with the analysis of the indoor radon concentration results measured in four schools of Trebinje city and taking into consideration their geological background and its characteristics. There have been 13 measurements and the results showed the range of 75 Bq/m3 to 4244 Bq/m3. Some of the indoor radon concentrations were very high, up to 15 times higher than recommended ones reaching the level of 300 Bq/m3. In each of the four schools there are spots with the high geogenic potential and, 38 % results show a concentration higher than 1100 Bq/m3, which further characterize this area as Radon Priority Area. From the geological point of view, the geological sheet Trebinje represents a part of Mesozoic and Paleogenic complex which build the outdoor Dinarides part. There are also different varieties of calcium carbonate and dolomite areas with sporadic occurrence of sandstones (pescari) and marlstones (laporci) accumulated at the end of the Paleogene period so that lithological content is pretty simple. The main part of the terrain is represented by sediments originated from Mesozoic and Paleogenic structures which appear along with greater dislocation in narrow strings.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80781427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"INFLUENCE OF MECHANICAL ACTIVATION ON IMPROVEMENT OF DISPERSION BEHAVIOR OF GОETHITE, QUARTZ AND CLAY MINERALS IN THE PRESENCE OF DIFFERENT DISPERSANTS","authors":"Ljiljana Tankosić, S. Sredić","doi":"10.7251/comen2301056t","DOIUrl":"https://doi.org/10.7251/comen2301056t","url":null,"abstract":"The paper focuses on the mechanical treatment of natural goethite,quartz and clay minerals, aiming at improving their dispersion behavior in the presence of different dispersants. The subject of research of mechanical activation is the change of the state of the material under the action of mechanical forces, whereby the newly created state of the material is defined as “activated”. The paper presents tests and analysis of the possibility of applying mechanoactivation of the mineral surface by grinding and multistage grinding in the planetary mill, for improving reactions with surface-active reagents. The results showed that the greatest resistance to grinding has the sample of goethite (Moss hardness 5-5.5). The influence of mechanoactivation was analyzed on the basis of the results of chemical analyzes and the ratio of sediment and overflow masses. Mechanical activation encourages better dispersion when activated minerals are treated with selected dispersants.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80831666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CONTAMINATING SUBSTANCES AS THE MAIN CONCEPT FOR RESEARCHING QUALITY AND WATER MANAGEMENT IN CONTEMPORARY SYSTEMS","authors":"S. Stevović, Jelena P. Marković","doi":"10.7251/comen2301030s","DOIUrl":"https://doi.org/10.7251/comen2301030s","url":null,"abstract":"Water on Earth is a vital element of living systems. Water is a medium that enables life and at the same time a medium in which a diverse eco systems exist. Natural waters contain dissolved gases, dissolved organic and inorganic substances and solid suspended materials. The quantities of dissolved and suspended substances are affected by: water temperatures, contact of water with the atmosphere, types of sediment the water is in contact, quantities of rainwater entering surface waters and quantities of waste substances, which are of anthropogenic origin. The results of water quality, according to the methodology of Eurowaternet - Lakes Aggregation of station data, were investigated and presented in a table form and by the location. The estimated value of water quality was obtained, expressed by the appropriate Water Quality Index. Water quality indicators are determined by the Serbian Water Quality Index method. The analyzes are presented by the frequency distribution of the indicators SWQI, nitrate, total phosphorus, ammonium and BOD5. Related to that research, as a result of the applied methodology and the fact that modern water supply systems in the Republic of Serbia have predominantly relied on groundwater reserves, and lately more and more on water abstraction from reservoirs and their use after treatment, a proposal for the management of raw water quality was given.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"124 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87872384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"APPLICATION OF INFORMATION TECHNOLOGIES IN FOOD PROCESSING","authors":"I. Grujić, B. Latinović","doi":"10.7251/comen2301092g","DOIUrl":"https://doi.org/10.7251/comen2301092g","url":null,"abstract":"Information technologies (IT) have become an important part of modern peoples activities. Many activities in food production processes are supported by different types of IT. The aim of this paper is to determine share of companies in Bosnia and Herzegovina (BiH), Serbia (SRB), North Macedonia (MKD) and Montenegro (MNE) that use some form of IT in their operations. Research was conducted in companies from the food sector in four countries in the Balkans. The research included 42 companies from BiH, 30 companies from Serbia, 14 companies from MKD and 6 companies from MNE. A special questionnaire was designed for the purposes of this research. The distribution of the questionnaire was done by e-mail, with a digital link for the users according to the form of the survey questionnaire that they should fill out (Microsoft Forms). The obtained results were statistically processed using IBM SPSS Statistics 26.During the research, authors determined areas in which companies already use IT, their plans related to the development of IT in the coming period and possibly for integration of existing and new IT solutions into a single information system. In their answers, the companies declared about the business areas in which they most often apply IT. Companies have developed and use several e-databases (the share of companies from each country is shown in relation to the number of companies that submitted complete survey questionnaires in the order of BiH, SRB, MKD and MNE): e-database of employees (88.1%); 96.7%; 100% and 100%, respectable), supplier base (73.8%; 100%; 100% and 83.3%, respectable), e-customer base (76.2%; 96.7%; 100% and 100%, respectable), e-base of resources for work (35.7%; 60.0%; 42.9% and 50.0%, respectable), e-base of reports on performed laboratory analyzes (35 .7%; 43.3%, 50.0% and 50.0%, respectively) etc. In the development of IT solutions, companies use different programming languages, mostly JAVA (59.3% of all companies surveyed) and C++ (37.4% of the total number of companies surveyed). The research showed that companies in the food sector in 4 Balkan countries use different forms of IT and that they have clear plans for their development and application in their business. It encourages the view that most companies are working on development of an integrated information system.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90571445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"USE OF 3D-BIOPRINTING IN TISSUE ENGINEERING SCAFFOLD PRODUCTION","authors":"N. Zdravković, M. Zivanovic, Nikolina Kastratović, Jelica Grujić, Katarina Virijević, D. Nikolić, N. Filipovic","doi":"10.7251/comen2301019z","DOIUrl":"https://doi.org/10.7251/comen2301019z","url":null,"abstract":"3D bioprinting is the hi-tech approach in tissue engineering science. Applying of modern 3D bioprinting systems allows production of tissue-like structures that could be used in regenerative medicine. Such tissues or primitive organ constructs could be used for substituting the parts of damaged organs, or for changing of organs in whole. Biomaterials must fulfill specific requirement to be applied in regenerative medicine: biocompatibility, biodegradability and possessing appropriate mechanical properties. PEG and PCL are widely used today in tissue engineering. We optimized wide range of PCL, PEG solutions alone and in combination. For 3D bioprinting was used Inkredible+ device. Optimization of experimental parameters for creating a scaffold that can be used in tissue engineering is a demanding process. As it is the first stage of developing the blood vessel, there is a high importance of ensuring they are formed well and with the desired properties. This innovative approach may be promising for further fabrication of a blood vessel.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76874456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NEURAL NETWORKS FOR SOLVING HUXLEY’S EQUATION","authors":"B. Milićević, M. Ivanovic, B. Stojanovic, Nenad Filipović","doi":"10.7251/comen2301043m","DOIUrl":"https://doi.org/10.7251/comen2301043m","url":null,"abstract":"Biophysical muscle models, also known as Huxley-type models, are appropriate for simulating non-uniform and unsteady contractions. Large-scale simulations can be more challenging to use because this type of model can be computationally intensive. The method of characteristics is typically used to solve Huxley’s muscle equation, which describes the distribution of connected myosin heads to the actin-binding sites. Once this equation is solved, we can determine the generated force and the stiffness of the muscle fibers, which may then be employed in the macro-level simulations of finite element analysis. In our paper, we developed a physics-informed surrogate model that functions similarly to the original Huxley muscle model but uses a lot less computational resources in order to enable more effective use of the Huxley muscle model.","PeriodicalId":10617,"journal":{"name":"Contemporary Materials","volume":"166 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75175748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}