Synthesis and characterization of DLPLG nanoparticles for controlled delivery of water-soluble vitamins

Biodegradable polymers have become the materials of choice for a variety of biomaterials applications. In particular poly (DL-lactide-co-glycolide) (DLPLG) nanoparticles have been studied for controlled released drug delivery. In this paper we are describing new method of obtaining the system for targeted and controlled delivery of the folic acid in the body. Folic acid (pteroyl-L-glutamic acid, vitamin B9) is a water-soluble vitamin essential in the human diet. It is an important cofactor in the synthesis of DNA and RNA, of dividing cells, particularly during pregnancy and infancy when there is an increase in cell division and growth. The DLPLG particles were obtained by chemical solvent/non-solvent method with PVP as a surfactant. The obtained DLPLG particles are non-agglomerated, uniform and with particles size in the submicron scale. The folic acid has been encapsulated into the polymer matrix by means of homogenization of the water and organic phases. The concentration of the folic acid in the water has been varied in order to obtain nanoparticles with different ratio of DLPLG and folic acid. The samples were characterized by Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM)

New Insights into Karst and Caves of Northwestern Zagros (Northern Iraq)

During 2002, several reconnaissance speleological explorations were undertaken by the authors and local enthusiasts in the karst of Northwestern Zagros in Northern Iraq. Some of the caves were visited for the first time and explored to a great depth by the scientists, while the Shanidar cave is a world-famous site representing one of the oldest discovered and investigated human settlements. The explored caves are located in well-karstified limestones of the Cretaceous age as well as in younger Eocene limestones. This paper contains the data from the nine largest caves. Their total explored lengths range from a few tens of meters up to several hundred meters. Four caves are fossil, containing only percolated water, while five represent still hydrogeologically active features. Two of them have resulted from the dissolution of carbonate or evaporate rocks stimulated by water oversaturated in H2S which migrated from deeper oil-bearing structures

Heuristics of Dictionary of technology and the crisis of Yugoslavia 1979-1982 in the context of the rise of postmodern culture

Докторска дисертација ,,Хеуристика Речника технологије и југословенска криза 1979–1982. у контексту успона постмодерне културе” обухвата петогодишње мултидисциплинарно истраживање историјске и тренутне мултикултуралне рецепције Речника технологије у контексту његовог хеуристичког потенцијала. Речник технологије објављен је 1981. као посебан тематски број часописа Видици. али је већ наредне године политички инкриминисан због идеолошког читања његове кодиране херменеутике технологије. Ово истраживање суочава нас са проблемом схватања интелектуалног склопа и разумевања духа времена у коме се Речник технологије појављује. Временски оквир у том смислу обухвата тренутак у коме је објављен, до сада врло оскудно истражен ужи период југословенске кризе (1979–1982), прве одзиве на садржину Речника, као и питање његовог антиципаторског потенцијала. Идеолошка осуда Речника технологије је била толико јака да се протегла и на период после окончања изградње социјализма тако да је провео тридесет и три године у забораву све до 2014. када је организован први научни скуп посвећен дијахронијском сагледавању овог списа што га је поставило у жижу обновљеног теоријског и академског интересовања. Српска хуманистичка мисао о технологији обликовала се још у делу Доситеја Обрадовића, али се та традиција у време друге Југославије скоро потпуно потискује. Зборник Технологија објављен 1980. као теоријска припрема Речника технологије представља обнову овог тока и први зборник филозофије технологије у српској култури. Речник технологије у томе има битно место јер мисли о технологији даје посебне теоријске и практичне одлике које се не могу наћи у списима тог времена. Он је исписан руком и илуминисан што одступа од продукције не само тог времена и парадоксално следи српски премодерни стваралачки канон бавећи се модерном мисли о технологији. Своје тумачење технолошке цивилизације Речник технологије даје кроз хипертекстуалну структуру сто шездесет и две речничке одреднице и разумевање преко сто педесет аутора које наводи. Он даје самосвојну антрополошку перспективу да се есхатологија технологије у неким својим тачкама не разликује од теолошких образаца који у много чему понављају своје премодерне изворе. У томе се огледа одважни постмодерни карактер овог дела који је снажно појачан чињеницом да овај рукопис у складу са средњовековним каноном и постмодерним концептом „смрти аутора” није потписан у отвореном коду. Циљ ове студије је да испита хеуристички потенцијал првог и за сада јединог речника посвећеног цивилизацијском разматрању технологије. Истраживање полази од идеје да сваки преломни историјски тренутак захтева речник који ће кроз разумевање промене парадигме покушати да пружи одговор на из тога произашлу кризу. Речник је у технологији коју не сматра само техничком већ и друштвеном појавом видео кризу личности и стога је разумевање проблема усмерио ка сагледавању језика, филозофије, уметности, теологије и технологије. Због тога га није лако одредити у формалном и значењском смислу и отуда је ово дело било неопходно промислити из перспективе укрштаја низа области и дисциплина. У дисертацији се указује на истовремено национални и универзални карактер Речника технологије што се потврђује у више равни истраживања и остварених научних резултата. Он је испитиван кроз рад на три научне конференције (две националне и једну међународну), кроз два зборника од националног и једног зборника (на енглеском језику) од истакнутог међународног значаја, ауторску изложбу с каталогом уз научну рецензију, документарном филму представљеном у више земаља, неколико научних радова објављених у земљи и иностранству, представљању Речника технологије на домаћим и међународним научним скуповима, као и предавањима у земљи и иностранству. Намера овог вишегодишњег истраживања је да на мултидисциплинарној равни понуди свеобухватно разумевање комплексности Речника технологије полазећи од друштвено-политичке историје до антропологије технологије, обухватајући у ширем смислу политичко, херитолошко-уметничко, социолингвистичко, премодерно- постмодерно, теолошко-технолошко читање овог дела. Рад у том смислу представља и актуелизацију садржаја које доноси Речником и покушај да се кроз његову оптику на крају сагледа матица догађаја који се јављају на обзору нових технологија у контексту успона постмодерне културе краја XX и почетка XXI века.The doctoral dissertation “Heuristics of Dictionary of Technology and the Crisis of Yugoslavia1979–1982 in the context of the rise of postmodern culture” includes five years of multidisciplinary research and evaluation of historical and contemporary multicultural reception of Dictionary of Technology in the light of its heuristic potential. Dictionary of Technology was published in 1981 as a special thematic issue of the journal Vidici, but it was politically supressed the following year due to the ideological reading of its coded hermeneutics of technology. This research needs to address the intellectual context and the spirit of the time Dictionary emerged in. Therefore, the study of Dictionary includes the scarcely researched period of Yugoslav crisis (1979–82), the first responses to its content, as well as the question of its anticipatory potential. The ideological condemnation of Dictionary of Technology was so strong that it extended beyond the end of the construction of socialism. Thus, this document spent thirty-three years in oblivion until 2014 when the first scientific conference dedicated to the diachronic examination of the script happened, placing it in the focus of the renewed theoretical and academic interests. Serbian humanistic thought about technology was shaped initially in the work of Dositej Obradovic, but this tradition was almost completely suppressed during the time of the second Yugoslavia. The volume Technology published in 1980 as a theoretical preparation of Dictionary of Technology represents the renewal of this flow and the first volume of philosophy of technology in Serbian culture. Dictionary of Technology holds a special place in this stream of ideas because it renders technology through special theoretical and practical approaches that cannot be found in the writings of that time. It is handwritten and illuminated which deviates from the production of that time; while addressing the modern thought about technology it paradoxically follows the Serbian premodern creative canon. Interpretation of technological civilization given by Dictionary of Technology has the hypertextual structure of one hundred and sixty-two terms and it refers comprehensively to over one hundred and fifty authors. It gives a distinct anthropological perspective that the eschatology of technology is in some aspects indistinguishable from theological patterns that, in many respects, repeat their premodern sources. This reflects the bold postmodern character of this work, strongly reinforced by the fact that this manuscript was not signed in accordance with the medieval canon and the postmodern concept of “author’s death”. The aim of this study is to examine the heuristic potential of the first and until now the only dictionary dedicated to the civilizational comprehension of technology. The research starts with the idea that every critical historical moment requires a dictionary that tries to respond to the crisis of a paradigm shift by understanding it. By considering technology not only a technical but also a social phenomenon, Dictionary perceived a crisis of selfhood and therefore focused its understanding of the problem on the perception of language, philosophy, art, theology, and technology. Hence, it is not easy to define it in formal and meaning sense, and that is why it was necessary to rethink this work from the perspective of the intersection of a number of fields and disciplines. The dissertation points at the simultaneous national and universal character of Dictionary of Technology, which is confirmed at several levels of the research and scientific results. Dictionary was field tested through three scientific conferences (two national and one international), two national and one internationally recognized publications, an author’s exhibition with a catalogue with scientific review, a documentary presented in several countries, several scientific papers published in the country and abroad, presentation of Dictionary at national and international scientific conferences, as well as lectures at home and abroad. The purpose of this multi-year research is to offer, on a multidisciplinary level, a comprehensive understanding of the complexity of Dictionary of Technology, from socio-political history to anthropology of technology, including in a broad sense political, heritological-artistic, sociolinguistic, premodern-postmodern, theological-technological readings of this work. This work is in this sense also an actualization of the content brought by Dictionary and an attempt to finally look through its optics into the matrix of events occurring on the horizon of new technologies in the context of the rise of postmodern culture of the late 20th and the early 21st century

The influence of organizational design on employee engagement in digital environment

U eri digitalizacije, dolazi do transformacionih promena u poslovnim modelima savremenih preduzeća, što implicira promene u celom organizacionom dizajnu. Smatra se da je za uspeh preduzeća, naročito u tehnološki intenzivnim delatnostima, bitna agilnost, usklađenost elemenata dizajna, i, posebno, angažovanost radne snage. Ljudski faktor postaje ključni izvor konkurentske prednosti i zato pitanja koja se tiču međuzavisnosti organizacionog konteksta i individualnih ishoda postaju sve značajnija. Osnovni cilj doktorske disertacije jeste utvrđivanje uticaja organizacionog dizajna na angažovanost zaposlenih u digitalnom poslovnom okruženju. Analiziran je uticaj dizajna posla, i to strukturalne, kognitivne i socijalne dimenzije posla, na angažovanost zaposlenih. Zatim je ispitan indirektan uticaj strategijske agilnosti, organizacione strukture, procesa i sistema, preko dimenzija dizajna posla, na angažovanost zaposlenih. Na kraju je testirano da li organizaciona identifikacija ima moderatorsku ulogu u uticaju dizajna posla na angažovanost zaposlenih. Nakon teorijskog razmatranja osnovnih fenomena i njihovih međusobnih veza, sprovedeno je empirijsko istraživanje na uzorku od 270 ispitanika, zaposlenih u 100 preduzeća u delatnosti informisanja i komunikacija u Republici Srbiji. Za prikupljanje podataka korišćena je anketa, a rezultati su obrađeni različitim statističkim tehnikama. Sprovedena je deskriptivna analiza uzorka, analiza pouzdanosti mernih skala bazirana na Kronbahovom koeficijentu alfa, konfirmativna faktorska analiza, kao i modeliranje strukturalnih jednačina. Rezultati su pokazali da sve tri dimenzije dizajna posla delimično utiču na angažovanost zaposlenih, kao i da je uticaj najjači u slučaju autonomije zaposlenih kao karakteristike posla. Utvrđeno je da svi elementi organizacionog dizajna, osim podele rada i formalizacije, imaju indirektan uticaj na angažovanost preko neke od karakteristika posla, kao i da organizaciona identifikacija u nekim vezama karakteristika posla i angažovanosti ima značajnu ulogu moderatora. Istraživanje ima relevantne teorijske i praktične implikacije. Teorijski doprinos se, između ostalog, ogleda u osvetljavanju značaja ispitivanja organizacionog dizajna kao multidimenzionalnog fenomena i njegovih kompleksnih reperkusija na individualnom nivou. Praktično, rezultati istraživanja mogu biti korisni menadžerima svih nivoa za dizajniranje organizacije koja će omogućiti visoke nivoe angažovanosti, naročito u digitalnom okruženju. Osnovna ograničenja se tiču veličine uzorka, kao i činjenice da je istraživanje sprovedeno na teritoriji jedne države, što predstavlja osnovu za proširenje dobijenih saznanja u budućim istraživanjima.In the era of digitalization, business models of modern companies are facing transformational changes, which affect the entire organizational design. Agility, organizational alignment and the workforce engagement are considered essential for business success, especially in technologically intensive industries. The human factor is becoming a key source of competitive advantage and therefore, issues concerning the interdependence of organizational context and individual outcomes are becoming increasingly important. The main goal of the doctoral dissertation is to determine the impact of organizational design on employee engagement in the digital business environment. The influence of job design, namely the structural, cognitive and social dimensions, on employee engagement was analyzed. Then, the indirect impact of strategic agility, organizational structure, processes and systems, through the dimensions of job design, on employee engagement was examined. Finally, it was tested whether organizational identification has a moderating role in the impact of job design on employee engagement. After the theoretical consideration of the basic phenomena and their mutual connections, an empirical research was conducted on a sample of 270 respondents, employed in 100 companies in the information and communication industry in the Republic of Serbia. A survey was used to collect data, and the results were processed using various statistical techniques. A descriptive analysis of the sample, an analysis of the measurement scales’ reliability based on the Cronbach's alpha coefficient, a confirmatory factor analysis, as well as structural equation modeling were performed. The results showed that all three dimensions of job design partially affect employee engagement, while the impact of job autonomy is the strongest. It was found that all elements of organizational design, except the division of labor and formalization have an indirect impact on engagement through some of the job characteristics. Also, organizational identification has a significant moderating role in some relationships between job characteristics and engagement. The research has relevant theoretical and practical implications. The theoretical contribution is inter alia reflected in highlighting the importance of organizational design as a multilayered phenomenon which has complex repercussions at the individual level. Practically, research results can be useful to managers at all levels in order to design an organization that will enable high levels of engagement, especially in the digital environment. The main limitations concern the size of the sample, as well as the fact that the research was conducted in one country, which is the basis for expanding the knowledge in future research

Stanje oralnog zdravlja dece obolele od nasledne distrofičke bulozne epidermolize

Background/Aim. Epidermolysis bullosa is a group of rare, genetic connective tissue diseases that cause blisters in the skin and mucosal membranes. The aim of this study was to evaluate the oral health status of patients with epidermolysis bullosa dystrophica and level of knowledge and opinion of parents about the implementation of preventive measures and quality of dental care of affected children. Methods. This study included a group of 17 patients from Serbia suffering from dystrophic epidermolysis bullosa and matched control group. Dental caries status was assessed using the Klein-Palmer index. Oral hygiene status was verified with oral hygiene indices, simplified plaque index, and calculus index as described by Green and Vermillion. The gingiva was assessed as healthy or inflamed (gingivitis) on the basis of any changes in color, shape, size and surface texture. The condition of oral mucosa has been registered on the basis of inspection of the lips, tongue, a floor of the mouth, mouth vestibule and palate. The level of knowledge and the impressions of parents about the application of preventive measures were investigated through two questionnaires specifically designed for this study. Results. In both dentitions, there was the highest percentage of caries teeth. In primary dentition average value of the modified plaque index was 1.4 ± 1.14 and modified calculus was 0.7 ± 1. On permanent teeth average plaque index was 2 ± 0.4, and average calculus 1.6 ± 0.6. Statistically, significant higher values were found in permanent dentition in percentage distribution of decayed, missing, filled teeth and also for plaque and calculus indices between affected children and the control group. Most common findings on mucosa were microstomia (76.5%) and ankyloglossia (88.2%). Conclusion. The absence of protocol between the treating physician and the dentist and not sufficiently informed parents are leading to inadequate dental care. The implementation of preventive measures is of most importance to decrease the risk of severe complications that are difficult to be managed.Uvod/Cilj. Bulozna epidermoliza je grupa retkih, genetski predisponiranih bolesti vezivnog tkiva koja se karakteriše formiranjem bula (mehurova) u koži i mukoznim membranama. Cilj rada bio je da se ispita stanje oralnog zdravlja dece obolele od distrofične bulozne epidermolize, kao i nivo znanja i mišljenje roditelja o primeni preventivnih mera i kvalitetu stomatološke zaštite obolele dece. Metode. U studiju je bilo uključeno 17 bolesnika sa distrofičnom buloznom epidermolizom iz Srbije i odgovarajuća kontrolna grupa. Stanje zuba ustanovljeno je Klein Palmerovim indeksom karijesnih, ekstrakovanih plombiranih zuba - KEP indeksom. Stanje oralne higijene analizirano je indeksima oralne higijene (pojednostavljeni plak indeks i indeks zubnog kamenca po Green-Vermillionu). Stanje gingive je na osnovu inspekcije ocenjivano kao zdrava gingiva ili gingivitis, u zavisnosti od toga da li su joj bili promenjeni boja, oblik, veličina ili struktura. Stanje oralne sluzokože evidentirano je na osnovu inspekcije usana, jezika, poda usne duplje, vestibuluma, plika i frenuluma, kao i mekog i tvrdog nepca. Nivo znanja i utisci roditelja o primeni preventivnih mera i kvalitetu stomatološke zaštite dece obolele od bolozne epidermolize, ispitivani su kroz dva upitnika specijalno dizajnirana za potrebe ove studije. Rezultati. U obe denticije bilo je najviše karijesno obolelih zuba. Za mlečnu denticiju prosečan modifikovani plak indeks iznosio je 1,4 ± 1,14, a modifikovani kalkulus indeks 0,7 ± 1. U stalnoj denticiji vrednosti prosečnog plak indesa i kalkulus indeksa redom su bile 2 ± 0,4 i 1,6 ± 0,6. Utvrđena je statistički značajna razlika u procentualnoj zastupljenosti karijesnih, ekstrahovanih i plombiranih zuba stalne denticije između dece obolele od bulozne epidermolize i kontrolne grupe, kao i za vrednosti plak i kalkulus indeksa. Najčešće promene oralne sluzokože bile su mikrostomija (76,5%) i ankiloglosija (88,2%). Zaključak. Odsustvo protokolarne saradnje između ordinirajućeg lekara i stomatologa, kao i nedovoljna informisanost roditelja, glavni su razlozi lošeg stanja oralnog zdravlja. Primena preventivnih mera je od najvećeg značaja kako bi se sprečio nastanak komplikacija koje je teško sanirati kod ove grupe bolesnika

Pojava glavobolja kod sporadične bolesti malih krvnih sudova mozga

Uvod: Bolest malih krvnih sudova (BMKS) mozga je čest nalaz kod pacijenata sa klasičnim vaskularnim faktorima rizika i povezana je sa motornim, kognitivnim i afektivnim poremećajima. Neuroradiološki, BMKS mozga se manifestuje lakunarnim infarktima i/ ili hiperintenzitetima bele mase (HBM), a moguća je i pojava mikrokrvarenja. Pored retkih naslednih oblika BMKS mozga, pacijenti sa glavoboljom, posebno migrenskog tipa, nalaze se u povećanom riziku za nastanak ovih lezija, mada je povezanost kompleksna i nedovoljno razjašnjena. Cilj: Cilj rada je identifikacija učestalosti i tipa glavobolja kod pacijenata sa sporadičnom BMKS mozga. Materijal i metode: Retrospektivnom studijom obuhvaćeno je 115 pacijenata sa dijagnozom BMKS mozga, lečenih i ispitivanih hospitalno na Odeljenju za cerebrovaskularne bolesti i rezistentne glavobolje Klinike za neurologiju Kliničkog centra Srbije, u periodu od 1. januara 2015. godine do 31. decembra 2017. godine. Analizirani su osnovni demografski podaci, tip glavobolje i nalaz na nuklearnoj magnetnoj rezonanci (NMR) mozga (prisustvo lakunarnih ishemija, HBM i ukupna težina lezija) standardnim statističkim testovima. Rezultati: Od ukupnog broja pacijenata uključenih u studiju, 44% je patilo od glavobolje. Lakunarni infarkti su uočeni kod 86,1% pacijenata, a HBM kod 46,1% pacijenta. Povezanost glavobolje i prisustva lakunarnih ishemija je bila na nivou statističkog trenda (p = 0,072), dok su pacijenti bez glavobolje imali tendenciju češće pojave HBM u odnosu na one sa glavoboljom (p = 0,065). Zaključak: Veliki broj pacijenata sa sporadičnom, arterioloskleroznom BMKS mozga se ujedno žali na glavobolju. Na NMR snimcima mozga prisustvo lakunarnih infarkta je vezano sa glavobolju kao simptom, a postojanje HBM je češće kod pacijenata bez glavobolje u anamnezi.Introduction: Cerebral small vessel disease (CSVD), a common finding in patients with vascular risk factors, is associated with motor, cognitive and affective disorders. Magnetic resonance imaging (MRI) brain scans of patients with CSVD include lacunar infarcts and/or white matter hyperintensities (WMH) and microhemorrhages. Aside from rare familiar forms of CSVD, patients with headaches, especially migraineurs, have an increased risk to develop these lesions, although this relationship is rather complex and yet to be fully elucidated. Aim: The aim of the study was to determine the frequency and type of headache in patients with CSVD. Material and methods: This retrospective study included 115 patients with CSVD diagnosis admitted at the Clinic of Neurology, Clinical Center of Serbia in the period January 1st, 2015 - December 31st, 2017. Baseline demographic data, headache type and MRI findings (ischemic lacunar infarctions, WMH, and overall lesion severity) were obtained. Data were compared between CSVD patients with headache and headache-free CSVD cases, with the use of standard statistical methods. Results: Among all patients included in this study, 44% had headaches. Lacunar infarcts were present in 86,1% and WMH in 46,1% cases. Correlation between headache symptoms and lacunar infarcts showed a trend towards statistical significance (p = 0.072) whereas headache-free patients more frequently had WMH, also approaching statistical significance (p = 0.065). Conclusion: A large number of arteriolosclerotic CSVD patients complain of different types of headaches. Based on MRI findings, lacunar infarcts are related to headache symptoms, and WMHs are more frequently present in patients with a negative history of headache

Pojava glavobolja kod sporadične bolesti malih krvnih sudova mozga

Uvod: Bolest malih krvnih sudova (BMKS) mozga je čest nalaz kod pacijenata sa klasičnim vaskularnim faktorima rizika i povezana je sa motornim, kognitivnim i afektivnim poremećajima. Neuroradiološki, BMKS mozga se manifestuje lakunarnim infarktima i/ ili hiperintenzitetima bele mase (HBM), a moguća je i pojava mikrokrvarenja. Pored retkih naslednih oblika BMKS mozga, pacijenti sa glavoboljom, posebno migrenskog tipa, nalaze se u povećanom riziku za nastanak ovih lezija, mada je povezanost kompleksna i nedovoljno razjašnjena. Cilj: Cilj rada je identifikacija učestalosti i tipa glavobolja kod pacijenata sa sporadičnom BMKS mozga. Materijal i metode: Retrospektivnom studijom obuhvaćeno je 115 pacijenata sa dijagnozom BMKS mozga, lečenih i ispitivanih hospitalno na Odeljenju za cerebrovaskularne bolesti i rezistentne glavobolje Klinike za neurologiju Kliničkog centra Srbije, u periodu od 1. januara 2015. godine do 31. decembra 2017. godine. Analizirani su osnovni demografski podaci, tip glavobolje i nalaz na nuklearnoj magnetnoj rezonanci (NMR) mozga (prisustvo lakunarnih ishemija, HBM i ukupna težina lezija) standardnim statističkim testovima. Rezultati: Od ukupnog broja pacijenata uključenih u studiju, 44% je patilo od glavobolje. Lakunarni infarkti su uočeni kod 86,1% pacijenata, a HBM kod 46,1% pacijenta. Povezanost glavobolje i prisustva lakunarnih ishemija je bila na nivou statističkog trenda (p = 0,072), dok su pacijenti bez glavobolje imali tendenciju češće pojave HBM u odnosu na one sa glavoboljom (p = 0,065). Zaključak: Veliki broj pacijenata sa sporadičnom, arterioloskleroznom BMKS mozga se ujedno žali na glavobolju. Na NMR snimcima mozga prisustvo lakunarnih infarkta je vezano sa glavobolju kao simptom, a postojanje HBM je češće kod pacijenata bez glavobolje u anamnezi.Introduction: Cerebral small vessel disease (CSVD), a common finding in patients with vascular risk factors, is associated with motor, cognitive and affective disorders. Magnetic resonance imaging (MRI) brain scans of patients with CSVD include lacunar infarcts and/or white matter hyperintensities (WMH) and microhemorrhages. Aside from rare familiar forms of CSVD, patients with headaches, especially migraineurs, have an increased risk to develop these lesions, although this relationship is rather complex and yet to be fully elucidated. Aim: The aim of the study was to determine the frequency and type of headache in patients with CSVD. Material and methods: This retrospective study included 115 patients with CSVD diagnosis admitted at the Clinic of Neurology, Clinical Center of Serbia in the period January 1st, 2015 - December 31st, 2017. Baseline demographic data, headache type and MRI findings (ischemic lacunar infarctions, WMH, and overall lesion severity) were obtained. Data were compared between CSVD patients with headache and headache-free CSVD cases, with the use of standard statistical methods. Results: Among all patients included in this study, 44% had headaches. Lacunar infarcts were present in 86,1% and WMH in 46,1% cases. Correlation between headache symptoms and lacunar infarcts showed a trend towards statistical significance (p = 0.072) whereas headache-free patients more frequently had WMH, also approaching statistical significance (p = 0.065). Conclusion: A large number of arteriolosclerotic CSVD patients complain of different types of headaches. Based on MRI findings, lacunar infarcts are related to headache symptoms, and WMHs are more frequently present in patients with a negative history of headache

Efficacy and limitations of ChatGPT as a biostatistical problem-solving tool in medical education in Serbia: a descriptive study

Purpose This study aimed to assess the performance of ChatGPT (GPT-3.5 and GPT-4) as a study tool in solving biostatistical problems and to identify any potential drawbacks that might arise from using ChatGPT in medical education, particularly in solving practical biostatistical problems. Methods ChatGPT was tested to evaluate its ability to solve biostatistical problems from the Handbook of Medical Statistics by Peacock and Peacock in this descriptive study. Tables from the problems were transformed into textual questions. Ten biostatistical problems were randomly chosen and used as text-based input for conversation with ChatGPT (versions 3.5 and 4). Results GPT-3.5 solved 5 practical problems in the first attempt, related to categorical data, cross-sectional study, measuring reliability, probability properties, and the t-test. GPT-3.5 failed to provide correct answers regarding analysis of variance, the chi-square test, and sample size within 3 attempts. GPT-4 also solved a task related to the confidence interval in the first attempt and solved all questions within 3 attempts, with precise guidance and monitoring. Conclusion The assessment of both versions of ChatGPT performance in 10 biostatistical problems revealed that GPT-3.5 and 4’s performance was below average, with correct response rates of 5 and 6 out of 10 on the first attempt. GPT-4 succeeded in providing all correct answers within 3 attempts. These findings indicate that students must be aware that this tool, even when providing and calculating different statistical analyses, can be wrong, and they should be aware of ChatGPT’s limitations and be careful when incorporating this model into medical education

AIR POLLUTION AS A RISK FACTOR FOR PNEUMONIA

Abstract. Air pollution has been shown to exacerbate respiratory diseases such as pneumonia. The aim of this research was to investigate the relationship between the longterm exposure to air pollution, as a risk factor, and the development of pneumonia in the population. The observed sample consisted of Niš citizens of different age groups who lived in area with high concentrations of air pollutants (investigated group) such as the Square of the October Revolution, as well as the citizens of Niška Banja (control group) which is the zone with the lowest concentration of air pollution. The investigation was carried out in the Public Health Institute in Niš, in the period between 2000 and 2012. A sample of 500 participants from Niš and Niška Banja was split into three age groups: up to 25, between 26 and 50, and above 51. Modified WHO, British MRC and American Thoracis Society questionnaires were run among the investigated and contol population sample group. A significance test was performed using a Mantel-Haenszel chi square (χ2) statistic. This test was used to check for a statistically significant difference between the prevalence of pneumonia between the investigated group and the control group across all age groups. The odds ratio (OR) and relative risk (RR) were determined. The statistical significance between measured concentrations in the air at observed measured spots was determined using the Student's t-test. The highest value of the chi square test was determined in the age group up to 25 (RR = 8,00, OR = 8,87, p0,05.The obtained results prove that the prevalence of pneumonia is significantly higher in the exposed population than in the non-exposed, especially among younger than 25 years old.  Key words: air pollution, pneumoni

Lowering unemployment through entrepreneurship: Global challenges and experience from Serbia

The unemployment rate is an exceedingly important indicator of the state of the economy and society. A high rate of unemployment demonstrates a low level of economic activity in the country, insufficient utilization of human resources, and a lower average quality of life in the country. The paper aims to examine the role and significance of entrepreneurial activity in reducing the unemployment problem in the Republic of Serbia with a specific focus on youth unemployment. The current situation including obstacles and motives of young people in the field of entrepreneurship will be examined with a focus on entrepreneurial education. The purpose of this paper is to contribute to knowledge and theory building in youth empowerment and entrepreneurship development