An ecologically acceptable "green" method of extraction cold-pressing is applied in order to reduce the use of organic solvents and preserve bioactive substances from raw material. Therefore, the ...work aimed to characterize cold-pressed oils obtained from non-intensively grown walnuts. Walnut samples were collected on the territory of Western and Central Serbia. 12 cold-pressed oils were used for the analysis. The content of water and volatile substances, index of refraction and specific absorbances, content of total phenols and antioxidant activity of the hydrophilic and lipophilic fraction of the oil were examined. Microbiological analyses included: the total number of bacteria, the total number of molds, and the presence of sulphite-reducing clostridia and Escherichia coli. In 11 oil samples, the content of water and volatile substances was in accordance with the national Rulebook. The refractive index varies from 1.4725 to 1.4745 for walnut oils. Cold-pressed walnut oils differ in the ranges of specific absorbances (1.08-1.75 at 232 nm and 0.04-0.15 at 270 nm). The content of total phenols in walnut oil was from 3.25 to 5.41 mg GAE/100 mL. The lipophilic fraction of oils showed a significantly higher antioxidant potential compared to the hydrophilic fraction. The results of DPPH* radical scavenging activities the lipophilic fraction was from 17.53% to 39.21%. In all tested walnut oil samples, the total number of bacteria and molds was low. The presence of sulfite-reducing clostridia and Escherichia coli was not detected. In addition to the general quality and biological value of the oils, it is important that they are microbiologically safe. Keywords: refractive index, specific absorbances, phenolic content, antioxidant capacity, microbiological evaluation Ekoloski prihvatljiva "zelena" metoda ekstrakcije hladno presovanje se primenjuje u cilju smanjenja upotrebe organskih rastvaraca i ocuvanja bioaktivnih materija iz sirovine. Stoga je i cilj rada da se okarakterisu hladno cedena ulja dobijena od neintenzivno gajenih oraha sakupljenih na teritoriji Zapadne i Centralne Srbije. U 12 dobijenih orahovih ulja ispitivan je sadrzaj vode i isparljivih materija, indeks refrakcije i specificne apsorbancije, sadrzaj ukupnih fenola kao i antioksidativna aktivnost hidrofilne i lipofilne frakcije. Mikrobioloske analize su obuhvatile: ukupan broj bakterija, ukupan broj plesni, prisustvo sulfitoredukujucih klostridija i Escherichia coli. U 11 uzoraka ulja sadrzaj vode i isparljivih materija bio je u skladu sa Pravilnikom za nerafinisana ulja. Rezultati su pokazali da se indeks refrakcije ulja kretao od 1,4725 do 1,4745. Takode, medu uzorcima su utvrdene varijacije u specificnim apsorpcijama na 232 i 270 nm (1,08-1,75 na 232 nm i 0,04-0,15 na 270 nm). Sadrzaj ukupnih fenola je iznosio od 3,25 do 5,41 mg GAE/100 mL. Lipofilna frakcija ulja pokazala je znacajno veci antioksidativni potencijal u poredenju sa hidrofilnom frakcijom. Antioksidativna aktivnost lipofilne frakcije ulja, merena DPPH* metodom, iznosila je od 17,53% do 39,21%. Ukupan broj bakterija i plesni bio je nizak. Prisustvo sulfitoredukujucih klostridija kao i Escherichia coli nije detektovano. Pored opsteg kvaliteta i bioloske vrednosti ulja, vazno je da su ulja mikrobioloski bezbedna. Kljucne reci: indeks refrakcije, specificne apsorbance, ukupni fenoli, antioksidativni kapacitet, mikrobioloska evaluacija
An ecologically acceptable "green" method of extraction cold-pressing is applied in order to reduce the use of organic solvents and preserve bioactive substances from raw material. Therefore, the ...work aimed to characterize cold-pressed oils obtained from non-intensively grown walnuts. Walnut samples were collected on the territory of Western and Central Serbia. 12 cold-pressed oils were used for the analysis. The content of water and volatile substances, index of refraction and specific absorbances, content of total phenols and antioxidant activity of the hydrophilic and lipophilic fraction of the oil were examined. Microbiological analyses included: the total number of bacteria, the total number of molds, and the presence of sulphite-reducing clostridia and Escherichia coli. In 11 oil samples, the content of water and volatile substances was in accordance with the national Rulebook. The refractive index varies from 1.4725 to 1.4745 for walnut oils. Cold-pressed walnut oils differ in the ranges of specific absorbances (1.08-1.75 at 232 nm and 0.04-0.15 at 270 nm). The content of total phenols in walnut oil was from 3.25 to 5.41 mg GAE/100 mL. The lipophilic fraction of oils showed a significantly higher antioxidant potential compared to the hydrophilic fraction. The results of DPPH* radical scavenging activities the lipophilic fraction was from 17.53% to 39.21%. In all tested walnut oil samples, the total number of bacteria and molds was low. The presence of sulfite-reducing clostridia and Escherichia coli was not detected. In addition to the general quality and biological value of the oils, it is important that they are microbiologically safe.
The paper presents an analysis and overview of vertex–frequency analysis, an emerging area in graph signal processing. A strong formal link of this area to classical time–frequency analysis is ...provided. Vertex–frequency localization-based approaches to analyzing signals on the graph emerged as a response to challenges of analysis of big data on irregular domains. Graph signals are either localized in the vertex domain before the spectral analysis is performed or are localized in the spectral domain prior to the inverse graph Fourier transform is applied. The latter approach is the spectral form of the vertex–frequency analysis, and it will be considered in this paper since the spectral domain for signal localization is well ordered and thus simpler for application to the graph signals. The localized graph Fourier transform is defined based on its counterpart, the short-time Fourier transform, in classical signal analysis. We consider various spectral window forms based on which these transforms can tackle the localized signal behavior. Conditions for the signal reconstruction, known as the overlap-and-add (OLA) and weighted overlap-and-add (WOLA) methods, are also considered. Since the graphs can be very large, the realizations of vertex–frequency representations using polynomial form localization have a particular significance. These forms use only very localized vertex domains, and do not require either the graph Fourier transform or the inverse graph Fourier transform, are computationally efficient. These kinds of implementations are then applied to classical time–frequency analysis since their simplicity can be very attractive for the implementation in the case of large time-domain signals. Spectral varying forms of the localization functions are presented as well. These spectral varying forms are related to the wavelet transform. For completeness, the inversion and signal reconstruction are discussed as well. The presented theory is illustrated and demonstrated on numerical examples.
Introduction: The outbreak of the disease caused by the novel coronavirus, SARS-CoV-2 named COVID-19 has spread throughout the world. The number of registered cases is increasing and almost no ...country or territory worldwide has been without any COVID-19 patient. The aim of this study was to examine the level of knowledge on the SARS-COv-2 and COVID-19 among medical students and to explore the differences in attitudes, practices and fear of COVID-19 among students with sufficient and students with insufficient knowledge.
Methodology: The cross-sectional study among the 1,722 medical students was conducted through an online platform of the Faculty of Medicine, University of Belgrade. The instrument used was a questionnaire with sections on socio-demographic characteristics, knowledge, attitudes and practices towards COVID-19 and the Fear of COVID-19 scale.
Results: Total of 1576 (91.50%) students were in the sufficient knowledge group. The multivariate logistic regression analysis showed that there was a significant association between the sufficient knowledge on COVID-19 and female sex (OR = 1.70, 95% CI = 1.18-2.45), age (OR = 1.10, 95% CI = 1.02-1.18), considering the preventive measures enforced in Serbia as good (OR = 2.57, 95% CI = 1.18-5.56), wearing the surgical mask outside of the household in the past 14 days (OR = 1.87, 95% CI = 1.22-2.87) and score on Fear of COVID-19 scale (OR = 0.94, 95% CI = 0.91-0.98).
Conclusions: Medical students showed good knowledge of COVID-19 and could be a part of the promotion of health education messages as a part of preventive measures.
Blood lead levels (BLLs) have been falling steadily worldwide due to restricted use of lead (Pb) and its compounds. although they remain above preindustrial Pb levels. Elevated BLL can still be found ...in children living near secondary Pb smelters that represent around 50% of Pb production. There have been no studies on Pb exposure in children living in Serbia ever since the 1980s. The aim of this study was to evaluate the BLLs in children living in two villages in Serbia (Zajača, the location of a secondary lead smelter, and Paskovac, 5 km away), identify the primary determinants of children’s BLLs, and investigate the impact of BLLs on children’s health symptoms and school achievement.
The study was conducted in 2011 on 127 children, aged 1–18 years, whose BLLs were measured using inductively coupled argon plasma mass spectrometry (ICP-MS).
The median BLL in children was 12 μg/dl, with a significantly higher value of 17.5 μg/dl in Zajača, compared to 7.6 μg/dl in Paskovac. Only 1 out of 75 and 12 out of 52 children from Zajača and Paskovac, respectively, had BLLs below the CDC recommended 5 μg/dl level. Living near the smelter resulted in 19 times, and having a father who works in the plant 4 times higher odds of elevated BLLs. No significant effects of elevated BLLs health symptoms were seen in this study.
BLLs of children living near a battery recycling plant in Serbia, an upper-middle income European country, were in the range and even higher than those of children living in developing countries. For the first time, the contribution of environmental and take-home lead exposure was quantified using mixed-effect modeling, and our results indicate a contribution of 25–40% of the take-home lead exposure to the BLLs of children living in the vicinity of a secondary lead smelter.
•Children living near a battery recycling plant had elevated blood lead levels (BLLs).•Children 0–6 years old living closest to the plant had the highest BLLs.•Higher lead exposure was found in children whose fathers worked in the plant.•The contribution of take-home lead exposure was between 25% and 40%.
Isoprenaline (ISO), a synthetic catecholamine and a β-adrenoceptor agonist, is widely used to develop an experimental model of myocardial injury (MI) in rats. The leading hypothesis for ISO-induced ...MI in rats is that it results from catecholamine overstimulation, oxidative stress, inflammatory responses, and development of cardiomyopathy during ISO administration. Folic acid (FA) reduces oxidative stress, improves endothelial function and prevents apoptosis, thereby contributing to cardiovascular protection. This study aimed to investigate the potentially protective effect of FA pretreatment on ISO-induced MI in rats.
For 7 days, adult male Wistar albino rats were pretreated with 5 mg/kg/day of FA. On the sixth and seventh days, MI in rats was induced by administering 85 mg/kg/day of ISO. Prooxidant markers in plasma samples, antioxidant capacity in erythrocyte lysates, cardiac damage markers, lipid profile, electrocardiography (ECG) and histopathological analysis were evaluated.
FA pretreatment significantly alleviated changes induced by ISO; it decreased the homocysteine and high-sensitivity troponin I level. FA moderately decreased the reactive oxygen species (ROS) levels (superoxide anion radical, hydrogen peroxide and thiobarbituric acid reactive substances) and improved the antioxidant activities of catalase, superoxide dismutase and reduced glutathione. ISO reduced the nitrite level and FA significantly alleviated this change.
It can be concluded that FA, as a mild antioxidant, could be an appropriate cardioprotective substance in the rat model of ISO-induced MI.
Field trials were set up in the Belgrade area (Serbia) in 2013 and 2014 to determine the effect of plant density on the natural incidence of potentially toxigenic fungi and the level of mycotoxins, ...aflatoxin B1 (AFB1), deoxynivalenol (DON) and fumonisins (FBs) in two Serbian maize hybrids of the FAO maturity group 700 (ZP 735 and NS Zenit). Three plant density treatments, namely, 55,000 plants ha−1 (PD1), 64,000 plants ha−1 (PD2) and 75,000 plants ha−1 (PD3), were evaluated.
The incidence of identified potentially toxigenic fungi of the genera Aspergillus, Fusarium, and Penicillium and the FB level increased significantly (P ≤ 0.01) at PD3. The effect of year was also significant (P ≤ 0.01) on the incidence of toxigenic fungi, as all fungal species had a higher incidence in 2014 than in 2013, with the exception of Aspergillus spp. that showed a significantly higher incidence in 2013. Levels of all tested mycotoxins were higher in 2014 than in 2013. The higher incidence of Fusarium graminearum, Fusarium proliferatum, Fusarium subglutinans, Fusarium verticillioides and Penicillium spp. and higher levels of AFB1 and FBs were observed in the hybrid ZP 735, whereas the hybrid NS Zenit had a higher incidence of Aspergillus spp. The effect of hybrids was not significant on the incidence of F. subglutinans and the DON level.
These results indicated that the highest investigated plant density increased the fungal incidence and the FB level, especially in 2014. Although the two hybrids originated from the same FAO group, they differed in their effects on some toxigenic fungi and mycotoxins.
•Influence of plant density on fungal contaminants of maize was investigated.•Plant density significantly affected the incidence of toxigenic fungi.•The highest plant density (75,000 plants ha−1) increased the level of fumonisins.•Interaction year × plant density had significant influence on mycotoxin levels.
Introduction. Persistent infection with highly oncogenic human papillomavirus is associated with premalignant cervical lesions and cervical cancer, as well as cancers of the vulva and vagina. The aim ...of the study was to determine the level of knowledge and attitudes towards human papillomavirus infection, its risk factors, clinical manifestations and the use of contraception. Material and Methods. A total of 355 first-year students of the Faculty of Medicine, University of Novi Sad, filled in a non-standardized, self-administered questionnaire designed for the purpose of this study. The collected data included: sexual history of the respondents, the use and knowledge of contraception, human papillomavirus infection, and human papillomavirus vaccine. Results. About 89% of students have heard of human papillomavirus infection, while 75.5degrees% of them knew that human papillomavirus infection is a sexually transmitted disease. Accurate knowledge about human papillomavirus infection was low, while female students showed higher levels of knowledge compared to the male (4.03 + or - 3.07 versus 5.56 + or -3.37; p < 0.01). Only 27.6degrees% of students knew that young women are at a higher risk of human papillomavirus infection, 45.9% of the respondents knew that the risk of human papillomavirus infection depends on the number of sexual partners, 34.09% of them knew that a condom does not provide complete protection against human papillomavirus infection, 53.5degrees% knew that human papillomavirus can cause cervical cancer, and only 19.7degrees% of students knew that human papillomavirus infection can cause penile cancer. Conclusion. The first-year medical students showed a lack of knowledge about human papillomavirus infection and human papillomavirus-related diseases. General education and health education of young people is necessary primarily in secondary schools, in order to preserve the reproductive health and prevent human papillomavirus-related cancers. Key words: Papillomavirus Infections; Uterine Cervical Neoplasms; Health Knowledge, Attitudes, Practice; Students, Medical; Risk Factors; Contraception; Sexual Behavior Uvod. Perzistentna infekcija visoko-onkogenim humanim papiloma virusom povezana je s pojavom premalignih cervikalnih lezija i raka grlica materice, kao i raka vulve i vagine. Cilj nam je bio da utvrdimo nivo znanja i stavove studenata medicine o infekciji humanim papiloma virusom, o njenim faktorima rizika, klinickim manifestacijama kao i upotrebi kontracepcije. Materijal i metode. 355 studenata prve godine Medicinskog fakulteta Univerziteta u Novom Sadu popunilo je nestandardizovani, za studiju konstruisan upitnik. Prikupljeni podaci ukljucivali su: anamnezu seksualnih odnosa ispitanika, znanje o kontracepciji i njena upotreba, znanje o infekciji humanim papiloma virusom i vakcini. Rezultati. Oko 89% studenata je culo za infekciju humanim papiloma virusom, dok 75,5% njih zna da se infekcija humanim papiloma virusom prenosi seksualno. Tacno poznavanje infekcije humanim papiloma virusom bilo je nisko, a devojke su pokazale visi nivo znanja u odnosu na muskarce (4,03 + or -3,07 vs 5,56 + or - 3,37; p <0,01). Samo 27,6% studenata zna da mlade zene imaju veci rizik od infekcije humanim papiloma virusom, 45,9% ispitanika zna da rizik od infekcije zavisi od broja seksualnih partnera, 34,09% zna da kondom ne predstavlja potpunu zastitu od infekcije humanim papiloma virusom, 53,5% zna da humani papiloma virus moze uzrokovati rak grlica materice, a samo 19,7% studenata zna da infekcija humanim papiloma virusom moze uzrokovati rak penisa. Zakljucak. Studenti prve godine medicine nemaju dovoljno znanja o infekciji i bolestima povezanim sa humanim papiloma virusom. Obrazovanje i zdravstveno prosvecivanje mladih ljudi, vec u srednjim skolama, potrebno je kako bi se ocuvalo reproduktivno zdravlje i sprecio nastanak karcinoma uzrokovanih humanim papiloma virusom. Kljucne reci: infekcije papiloma virusom; karcinom grlica materice; znanje o zdravlju, stavovi, praksa; studenti medicine; faktori rizika; kontracepcija; seksualno ponasanje
Introduction. Persistent infection with highly oncogenic human papillomavirus
is associated with premalignant cervical lesions and cervical cancer, as
well as cancers of the vulva and vagina. The aim ...of the study was to
determine the level of knowledge and attitudes towards human papillomavirus
infection, its risk factors, clinical manifestations and the use of
contraception. Material and Methods. A total of 355 first-year students of
the Faculty of Medicine, University of Novi Sad, filled in a
non-standardized, self-administered questionnaire designed for the purpose
of this study. The collected data included: sexual history of the
respondents, the use and knowledge of contraception, human papillomavirus
infection, and human papillomavirus vaccine. Results. About 89% of students
have heard of human papillomavirus infection, while 75.5% of them knew that
human papillomavirus infection is a sexually transmitted disease. Accurate
knowledge about human papillomavirus infection was low, while female
students showed higher levels of knowledge compared to the male (4.03 ? 3.07
versus 5.56 ?3.37; p < 0.01). Only 27.6% of students knew that young women
are at a higher risk of human papillomavirus infection, 45.9% of the
respondents knew that the risk of human papillomavirus infection depends on
the number of sexual partners, 34.09% of them knew that a condom does not
provide complete protection against human papillomavirus infection, 53.5%
knew that human papillomavirus can cause cervical cancer, and only 19.7% of
students knew that human papillomavirus infection can cause penile cancer.
Conclusion. The first-year medical students showed a lack of knowledge about
human papillomavirus infection and human papillomavirus-related diseases.
General education and health education of young people is necessary
primarily in secondary schools, in order to preserve the reproductive health
and prevent human papillomavirus-related cancers.
Oxidative status of maternal blood represents an important parameter of pregnancy that is involved in both, regulation of physiological processes and (if significantly altered) development of ...different pregnancy complications. Inherited thrombophilias represent genetic disorders that increase the risk of thromboembolism in pregnancy. Little is known about the impact of thrombophilia on the oxidative status of maternal blood. In this study, we analyzed oxidative status of blood of 56 women with pregnancies burdened by inherited thrombophilias. The status was established at three different trimesters using biochemical assays and electrochemical measurements, and it was compared to 10 age- and trimester-matching controls. Activities of superoxide dismutase, catalase, and glutathione reductase in the 1.sup.st and the 2.sup.nd trimester of thrombophilic pregnancy were lower than controls. Also, there was less oxidation in the plasma, according to higher concentration of reduced thiols and lower oxidation-reduction potential. Therefore, it appears that thrombophilic mothers do not experience oxidative stress in the circulation in the first two trimesters. However, the rise in GPx, GR and SOD activities in the 3.sup.rd trimester of thrombophilic pregnancy implies that the risk of oxidative stress is increased during the late pregnancy. These results are important for developing antioxidative treatment that could tackle thrombophilia-related pregnancy complications.
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