Биофизика (учебник наменет за студентите по медицински науки)

Учебникот е наменет за студентите по медицинските науки. Неговата основна цел е да ги објасни концептите на биофизиката на човечкиот организам како и физичките основи на некои медицински дијагностики и тераписки методи. Содржината е организирана, според областите на физиката, во седум тематски целини: механика на цврсто тело, механика на флуиди, звук, транспортни процеси, електрични и магнетни појави, оптика и јонизирачки зрачења. За разбирање на текстот, доволни се основни предзнаења стекнати од кое било средно образование. Секоја тема содржи поглавја структурирани така што се почнува од физиката, потоа биофизиката на одреден дел од телото и на крај медицинската дијагностика и терапија. За секое биофизичко толкување на одреден процес се вклучени неопходните елементарни објаснувања од анатомијата и физиологијата. Одредени процеси во човечкиот организам се анализирани и квантитативно. По неколку примери во секоја тема го илустрираат пристапот, применувајќи исклучително алгебра и тригонометрија. Напредокот на медицинската дијагностика и терапија, меѓу другото, се должи и на примена на физичките методи. Некои од нив, со нивните предности и ограничувања, се објаснети во соодветните теми. Во согласност со наставната содржина, биофизиката е основа за разбирање, првенствено на физиологијата и патофизиологијата, но понатаму и за радиологијата, нуклеарната медицина, физикалната терапија и радиотерапијата. Пишувањето учебник е работа која бара сериозен пристап, особено кога станува збор за мултидисциплинарна наука како што е биофизиката. Имајќи предвид дека повеќето од студентите по медицински науки не се премногу мотивирани за физика, пишувањето беше голем предизвик. Учебникот претставува преработка на мојата претходно објавена скрипта по биофизика, направена врз основа на согледувањата на резулатите од проверките на знаењата на студентите. Некои од појавите се изземени од учебникот, а некои се дообјаснети со голем број примери и илустрации. На крајот од секоја тема се вклучени и примери за самостојна проверка на знаењето

Effects of the Covid-19 pandemic on the visits frequencies in Emergency Service Skopje

Abstract: The pandemic caused by the COVID -19 virus has affected human health, consequently the health system and health services, both worldwide and in the Republic of North Macedonia. The idea for this research was therefore to examine the impact of the conditions imposed by the pandemic on the visits of the Emergency medical service in Skopje.For this purpose, the frequencies of visits with transport to hospital and just visits, as well as the frequencies of emergency calls and calls only for transport in the periods: before the pandemic (March 2019-February 2020) and during the pandemic (March 2020 to February 2021) were analyzed. The overall number of visits was further analyzed by categories: age and gender.In the period from March 2019 to March 2021, a total of 49,930 visits were performed, of which 24,115 were performed during the pandemic and 25,815 before. In the same period, a total of 13,835 emergency calls were answered, of which 6,434 were during the pandemic and 7,401 before; a total of 9780 calls for transport of patients were carried out, during the pandemic 5602 and 4178 before the pandemic. The analysis showed that the number of transports was increased and the number of emergency calls decreased during the pandemic compared to the pre-pandemic period, while the number of visits during and before the pandemic did not differ significantly. Concerning age and gender, the analysis showed that the number of visits to children, men aged 20 to 40 and women over 60 years was significantly reduced compared to pre-pandemic visits, while there was no difference in other age groups. The contributions of visits related to certain diagnostic and a particular age group are discussed in this paper.We found that the pandemic has not influenced the pace of work, apart from the conditions, only the association between the kind of calls and the diagnoses for which the visits were made has practically changed. During the pandemic, most visits for males and females over 40 were related to COVID diagnosis, while for children, men and women under 40, accidents were the most common caus

Diurnal and spatial variations of radon and its influence on ionization of the nearground atmospheric layer

The most abundant and efficient source of air ionization in the lower layer of the atmosphere is radon. As an alpha emitter, radon plays cruciant role in the earth atmospheric electricity. Besides physical, radon and ions have a significant biological role concerning human health: radon is health hazard while the ions are beneficial ingredient of the air we breathe. Measurements were made using continual radon monitor Rad-7 and air ion counter CDI-06. Diurnal and spa¬tial variations of both atmospheric constitutens are mutually related and dependant mo¬stly on radon exhalation potential, meterological parameters, aerosol con¬cen-tra¬ti¬on and formation of temperature inversion layer. Indoor concentrations are re¬la¬ted to radon accumulation and partiallz influenced by external radon concentratio

Radiological impact of surface water and sediment near uranium mining sites

The aim of this study is to assess the radiological impact of surface water and sediment around uranium mining sites 20 years after their closing. The areas under observations are 31 former classical underground uranium mining and exploratory sites in Bulgaria, named as objects. The extraction and processing of uranium ores in the Republic of Bulgaria were ended in 1992. To assess the radiological impact of radionuclides field expeditions were performed to sample water and bottom sediment. The migration of uranium through surface water was examined as one of the major pathways for contamination spread. The range of uranium concentration in water flowing from the mining sites was from 0.012 to 6.8 mgU l −1 with a geometric mean of 0.192 mgU l . The uranium concentrations in water downstream the mining sites were approximately 3 times higher than the background value (upstream). The concentrations of U nat , 226 Ra, 210 Pb, and 232 Th in the sediment of downstream river were higher than those upstream by 3.4, 2.6, 2, and 1.7 times, respectively. The distribution coefficient of uranium reflects its high mobility in most of the sites. In order to evaluate the impact on people as well as site prioritization for more detailed assessment and water management, screening dose assessments were done

Results of the national radon indoors survey in Bulgaria

Purpose: To present the results of the annual average indoor radon concentrations from National survey in Bulgarian regions. Variability of measured data between 28 regions was investigated in order to achieve the preliminary assessment the distribution of indoor radon concentration through Bulgarian territory. Argument: The National survey on average radon concentration in Bulgarian dwellings was carried out from 2015 to 2016, with the co-operation of the Regional Health Inspectorate under the National Radon Program. Data were collected through personal interviews with residents and deployment of alpha track detectors for one year through two phases. The first phase was from March 2015 to December 2015 and second from December 2015 to April 2016 approximately. For each region 100 detectors were distributed and spread to villages in regions depending on the population. The measurements were completed in 2775 dwellings. The distribution of indoor radon levels has been found to be log-normal with a geometric mean (GM) of 81.6 Bq•m−3 and a standard deviation of 2.1. The highest value of the radon concentration found was 1314 Bq•m−3 in the Sliven region. Region with high GM of 184 Bq•m−3 and a standard deviation of 1.7 is Yambol in Southeast Bulgaria. In about 6% of the houses, the radon concentration was found to be in excess of the recommended reference value of 300 Bq•m−3, suggested by the Council of the European UnionCommission in in new EU Directive 2013/59/Euratom. Conclusion: The data from National survey are the first systematic results and are received to complete the National Program, which will finish in 2017. The preliminary results clearly show that the national action plan to address long-term risks from radon exposures should be developed taking into account the results achieve in this program and in accordance with the new Directive 2013/59/Euratom

Developing a method for predicting radon concentrations above a reference level in new montenegrin buildings

Dependence of indoor radon concentrations (IRCs) in the ground floors of 1200 buildings across Montenegro on 11 factors was analyzed. A group of 734 buildings, for which none of the analyzed factors was missing, was further analyzed using the logistic regression method, in order to develop a prediction model for IRC occurrence above the national reference level for new buildings (200 Bq/m3). Applying the forward stepwise method, and based on likelihood ratios, five explanatory variables—municipality, type of building, presence of basement, window frames, and period of construction—were selected for including into the final logistic regression model for predicting probability of IRC > 200 Bq/m3. The final model explained 77.1% of the observed IRCs, while the obtained Area under the Curve of 0.8018 classified the model as having a very high predictive ability. Achieving similar values for both the final prediction model and the validation model, for sensitivity, specificity, and accuracy, confirmed the applicability of the developed model

Annual and seasonal variations of indoor radon concentration in Skopje (Republic of Macedonia)

This paper presents the results of a survey of indoor radon concentrations in the dwellings of 10 Municipalities in the Skopje: the capital and the largest city of the Republic of Macedonia (600 000 habitants). The indoor radon concentrations were measured during the four successive seasons from December 2008 to December 2009 using integrating passive alpha track-etch detectors with an exposure period of three months. The annual mean indoor radon concentration in each measuring site was estimated as an arithmetic mean from the four individual measurements. The measurements were completed for 124 dwellings, of which 112 dwellings revealed indoor radon concentrations lower than 200 Bq m−3, and 3 showed radon concentrations in excess of 400 Bq m−3. The annual mean indoor radon concentrations were found to be log-normally distributed, ranging from 18 to 502 Bq m−3. The geometric mean value of the indoor radon concentration in Skopje region was estimated to be 83*/1.94 Bq m−3. The results of analysis of variance showed statistically significant differences among annual mean values of the indoor radon concentrations of among the different municipalities (p=0.021). The influence of the factors linked to building characteristics in relation to the annual mean of indoor radon concentration was also a subject to examination. The factors which allow differentiation into subgroups (significance level p<0.05) were: the floor level (p<0.0001), presence of basement (p<0.0001), and type of heating (p=0.004). Seasonal dependence of indoor radon concentration was observed. The minimum indoor radon concentrations were found in the summer season whereas maximum levels were observed in the winter season (p< 0.0001)

Antibacterial Activity of Selected Silver Nanoparticles Coatings - Our Initial Experience

Nanoparticles exhibits chemical and physical properties significantly different to their macro-scale counterparts composed of the same substance (due higher surface/volume ratio, colour, solubility, diffusivity,material strength, toxicity, thermodynamic, magnetic, optical and other properties) and may have unique impacts on health and environment. Extremelly small size (1-100 nm) enables them to enter the human body through usual or unusual routes, pass through cell membranes, or cross the blood-brain barrier. Gravity loses impact and importance, surface tension and Van der Waals constants has more importance in system of nano particles. Nanotechnology is already used in various applications, with potential tobe applied at any stage in food industry: production, preservation, processing, packaging,transport, nanobarcodes for food authenticity and tracing, labelling, keeping the quality of food products, extend the products shelf-life, removal of undesirable tastes, flavours or allergens from food products, nano (bio)sensors for food safety, water filtration. Risks of nanotechnology are still unknown and unpredictable. Initial scientific studies showed negative effects on living organisms and a potential for serious threat to human health. Authorities of the most developed countries, have set up, guidance documents and procedures for nanoenabled products based on existing regulations, appropriate in vitro and in vivo ADME studies (absorption, distribution, metabolism and excretion) and requirements for standardised and harmonised analytical test methods for proper risk assesments, clear identification and characterization of nano-hazards. Nanotechnology in medicine (Nanomedicine) apply for rapid and sensitive detection of pathogenic bacteria and low levels of viruses, in small sample volumes, at lower costs than current in-use technologies. This advance in early detection enables accurate and prompt treatment. Nano-robots to make repairs at the cellular level are under development. Rapid and sensitive detection methods, based on nano (bio) senzors, are developed for food-borne pathogens E. coli, especially E. coli O157:H7, S. aureus, S. typhimurium, C. jejuni, E. cloacae, B. subtilis, L. monocytogenes. Detection sensor to detect bacterial biofilm formation on surfaces are under development. New strategies to combat multydrug resistant microorganisms (MDR) are urgently needed and nanomaterials are very promising approach. Small size provides large surface of nanoparticles and at least 50% of molecules will react to the microorganisms. Metal nanomaterials (silver, gold, copper, titanium, zinc, magnesium,cadmium, and alumina) possess advantage of unique antimicrobial activities. Scientists offers also new complex antibacterial and antiviral nano systems on the basis of metal oxides or intermetallic oxide compounds (such as TiO2, ZrO2, SnO and SiO2). Inside the human body ionic silver quickly combines with chloride to form an insoluble compound called silver chloride which is far less reactive than metallic silver nanoparticles. Some studies established that silver ions has strongest bactericidal effect, cooper and gold weaker one. In our preliminary study on antibacterial activity of several different compositions of nanoparticle coatings (titanium, inox and silver), we found antimicrobial activity of silver, double composition of titanium and silver against Staphylococcus aureus and Staphylococcus epidermidis, but not for E. coli, Pseudomonas aeruginosa, Listeria monocytogenes and Candida albicans. More extensive studies will follow. Key words: Nanoscience, nanoparticles, silver, ions, biofilm, antimicrobial, antibiotic, resistance

First Evolution of Radon Concentrations Spatial Distribution based on the geological parameters and multiple linear regression method in schools of Sjenica community, Western Serbia (Balkan area)

Purpose: The paper deals with the analysis of radon survey in 34 schools over Sjenica community, in West Serbia, aiming at systematically continuation of previously performed surveys (2008-2010) in the 340 schools in South Serbia, as the project activities (Serbian Ministry of Education Since and Technical Development) considering optimization of the design of a national survey and improving the knowledge of radon distribution in Serbia. In addition , the results of this survey triggered, based on Sjenica (Pestar) region complex geology and measured annual Rn concentrations, an attempt of the explanation of radon spatial variation in Sjenica community by multivariable linear regression (MLR) method in total of 36 public buildings investigated (beside schools, the kindergarten and meterological station). Argumatation: Schools are workplaces which are subject to Rn regulations (EC 2014,BSS).Among other, the BSS require establishing reference levels for long-term indoor Rn concentration, not exceeding 300 Bq/m3 for both dwellings and workplaces. The 36 public buildings were surveyed the whole year in the Sjenica community in West Serbia by long term measurements with CR-39 detectors (commercially named Gamma 1, Landaurer, Sweden). Sjenica community is the largest community of 1059 km2 surface in Serbia and it was found that indoor radon (Rn) lower than 100 Bq/m3 are most probable and although with lower probability,that Rn higher than action level of 300 Bq/m3could occur in 14% of the buildings , indicating potential of the investigated area as high natural background area. The highest measured indoor Rn concentration was 1130 Bq/m3. Conclusion: The predictive model was developed, in order to determine how geological parameters best merge to explain the indoor radon concentrations. The results of this investigation highlight that it is possible to predict indoor radon concentrations using the geological data to an acceptable level of accuracy with a limited number of measurements. There is potential of the investigated area as high natural background area

Analysis of the spatial distribution of the indoor radon concentration in school's buildings in Plovdiv province, Bulgaria

This paper presents an evaluation of the indoor radon spatial variation between and within school buildings. Radon measurements were carried out in 331 rooms of 16 school buildings in 5 municipalities of Plovdiv province, Bulgaria. They were performed with CR-39 nuclear track detectors exposed over an 8-month period from September 2018 to April 2019. The arithmetic and geometric means together with corresponding standard deviation and geometric standard deviations of the indoor radon concentration were 160 ± 175 Bq/m3 and 108 */2.35 Bq/m3, respectively. The best data fit was achieved with a Weibull 3-parameter function (Kolmogorov-Smirnov test, p = 0.2916). The effect of the school location and various building characteristics on the indoor radon concentration distribution within a province was investigated. The analyses showed that the factor “year of building construction”, which is in general related with the technical condition of the building, imposed the highest impact on the indoor radon concentration difference between schools. The vertical and horizontal components of the indoor radon spatial variability within a school were analysed as well. The results concerning the radon variation within schools could be used to optimize future radon school surveys. In this paper, quality control for indoor radon measurement procedures and radon health impact assessments was included