Prisustvo i rasprostranjenost virusa duvana u Srbiji

Infection with a large number of plant viruses could imperil tobacco yield and quality. Tobacco is a natural host for more than 20 viruses, among which the most important and economically harmful are tobacco mosaic virus (TMV), tomato spotted wilt virus (TSWV), cucumber mosaic virus (CMV), potato virus Y (PVY), alfalfa mosaic virus (AMV), tobacco ringspot virus (TRSV), tobacco each virus (TEV) and tobacco vein mottling virus (TVMV). The occurence and distribution of tobacco viruses were investigated for 4 years (2002- 2005). During this period many different tobacco growing localities in Vojvodina and central Serbia were monitored and samples showing virus symptoms were collected. The collected samples were tested by DAS ELISA using polyclonal antisera, specific for the detection of PVY, TSWV, TMV, CMV, AMV and TRSV. The results obtained for the tobacco virus distribution during these four years of investigation proved the presence of four economically important viruses in our country, whose frequencies varied from year to year. In 2002, 2003 and 2004, the most frequent was TSWV (86.84%; 79% and 49.56%, respectively), while in 2005 PVY was prevalent (56.16%). All viruses detected in the samples tested were present in single or mixed infections. A corellation was established between the field symptoms on tobacco and the virus causal agents. The results obtained showed that TSWV and PVY were the most important tobacco viruses in our country, so that further research of tobacco virus diseases should be directed towards their more detailed characterization.Prinos i kvalitet duvana mogu da budu ugroženi usled zaraze velikim brojem fitopatogenih virusa. Duvan je prirodni domaćin preko 20 virusa od kojih su najznačajniji i ekonomski najštetniji virus mozaika duvana (Tobacco mosaic virus, TMV), virus bronzavosti paradajza (Tomato spotted wilt virus, TSWV), virus mozaika krastavca (Cucumber mosaic virus, CMV), virus crtičastog mozaika krompira (Potato virus Y, PVY), virus mozaika lucerke (Alfalfa mosaic virus, AMV), virus prstenaste pegavosti duvana (Tobacco ringspot virus, TRSV), virus graviranosti duvana (Tobacco each virus, TEV) i virus šarenila nerava duvana (Tobacco vein mottling virus, TVMV). Prisustvo i rasprostranjenost virusnih zaraza duvana su ispitivani tokom četiri godine, od 2002. do 2005. Pregled i sakupljanje uzoraka sa simptomima obavljeno je u više različitih lokaliteta gajenja duvana u Vojvodini i centralnoj Srbiji. Sakupljeni uzorci su testirani DASELISA metodom na prisustvo PVY, TSWV, TMV, CMV, AMV i TRSV. Dobijeni rezultati ispitivanja ukazuju na prisustvo četiri ekonomski značajna virusa duvana u našoj zemlji i to: TSWV, PVY, TMV i CMV, čija je učestalost po pojedinim godinama i lokalitetima bila različita. Tokom 2002, 2003. i 2004. godine najčešće detektovan virus bio je TSWV (86,84%; 70%, odnosno 49,56%), dok je 2005. godine prevalentan virus bio PVY (56,16%). Svi virusi čije je prisustvo utvrđeno u ispitivanim uzorcima nalazili su se u pojedničnim ili mešanim infekcijama. Bez obzira na izraženu varijabilnost u ispoljenim simptomima virusnih zaraza na duvanu, ustanovljena je zavisnost tipa ispoljenih simptoma od virusa prouzrokovača. Sprovedena ispitivanja pokazala su da su TSWV i PVY najznačajniji virusi duvana u našoj zemlji, tako da buduća ispitivanja viroza duvana treba da budu usmerena ka detaljnijoj karakterizaciji ovih ekonomski štetnih virusa

Phenolic Compounds in Field Horsetail (Equisetum arvense L.) as Natural Antioxidants

In this paper, the study of antioxidant activity and phenolic composition of three different extracts (EtOAc, n-BuOH and H2O) of field horsetail (Equisetum arvense L.) is presented. The antioxidant activity has been evaluated measuring the total reducing power (expressed by Ascorbate Equivalent Antioxidant Capacity - AEAC), inhibition of lipid peroxidation, and free radical scavenging capacity (RSC) towards 2,2-diphenyl-1- picrylhydrazyl (DPPH radical) and nitric oxide (NO), respectively. In addition, the total flavonoid content (TFC) and phenolic constituents of each extract have been determined. The results obtained show that the highest RSC regarding both DPPH and NO radicals is expressed by EtOAc extract (EC50=2.37 μg/mL and EC50=90.07 μg/mL, respectively), and the lowest by H2O extract (EC50=37.2 μg/mL and EC50>333.33 μg/mL, respectively). n- BuOH extract showed the highest total reducing power (AEAC=13.40 μg/mL). Differences in the phenolic composition of examined extracts are found comparing the HPLC chemical profiles. Although, isoquercitrin is the main flavonoid in both EtOAc and n-BuOH extracts, a considerable amount of di-E-caffeoyl-meso-tartaric acid was presented in the n-BuOH extract. In H2O extract high content of phenolic acids and low percentage of flavonoids were detected

Chemical Composition, Antioxidant and Antibacterial Properties of Achillea collina Becker ex Heimerl s.l. and A. pannonica Scheele Essential oils

The in vitro antioxidant and antimicrobial activities of two Achillea millefolium (Adanson) Koch s.l species essential oils (A. collina Becker ex Heimerl s.l. and A. pannonica Scheele, Asteraceae) originating from the Golija and Radan mountains (Serbia) were investigated. The chemical profiles of the essential oils were evaluated by GC-MS. Antioxidant activity was assessed as free radical scavenging capacity (RSC) towards 2,2-diphenyl-1-picrylhydrazil (DPPH) radicals, together with effects on lipid peroxidation (LP). Antibacterial activity was examined on 21 bacterial strains. Based on the chemical composition of the essential oil, A. collina s.l. from Mount Golija was classified as a chamazulene chemotype (tetraploid). The high percentage of oxygenated monoterpenes and absence of azulene in the essential oil obtained from A. pannonica from Radan pointing that this population is octaploid. Essential oil of A. pannonica expressed stronger antimicrobial activity on almost all tested bacteria. Furthermore, this essential oil expressed higher scavenging effects on DPPH radical (IC50 = 0.52 comparing to 0.62 μg/mL). Only in the LP evaluation, essential oil of A. collina s.l. from Golija exhibited stronger antioxidant activity (IC50 = 0.75 comparing to 2.12 μg/mL)

Chemical composition, antioxidant and antibacterial properties of Achillea collina Becker ex Heimerl s.l. and A. pannonica scheele essential oils

The in vitro antioxidant and antimicrobial activities of two Achillea millefolium (Adanson) Koch s.l species essential oils (A. collina Becker ex Heimerl s.l. and A. pannonica Scheele, Asteraceae) originating from the Golija and Radan mountains (Serbia) were investigated. The chemical profiles of the essential oils were evaluated by GC-MS. Antioxidant activity was assessed as free radical scavenging capacity (RSC) towards 2,2-diphenyl-1-picrylhydrazil (DPPH) radicals, together with effects on lipid peroxidation (LP). Antibacterial activity was examined on 21 bacterial strains. Based on the chemical composition of the essential oil, A. collina s.l. from Mount Golija was classified as a chamazulene chemotype (tetraploid). The high percentage of oxygenated monoterpenes and absence of azulene in the essential oil obtained from A. pannonica from Radan pointing that this population is octaploid. Essential oil of A. pannonica expressed stronger antimicrobial activity on almost all tested bacteria. Furthermore, this essential oil expressed higher scavenging effects on DPPH radical (IC50 = 0.52 comparing to 0.62 mu g/mL). Only in the LP evaluation, essential oil of A. collina s.l. from Golija exhibited stronger antioxidant activity (IC50 = 0.75 comparing to 2.12 mu g/mL)

The Predictive Value of Risk Factors and Prognostic Scores in Hospitalized COVID-19 Patients

Introduction: Risk stratification in patients with COVID-19 is a challenging task. Early warning scores (EWSs) are commonly used tools in the initial assessment of critical patients. However, their utility in patients with COVID-19 is still undetermined. Aim: This study aimed to discover the most valuable predictive model among existing EWSs for ICU admissions and mortality in COVID-19 patients. Materials and methods: This was a single-center cohort study that included 3608 COVID-19 patients admitted to the University Clinical Hospital Center Bezanijska Kosa, Belgrade, Serbia, between 23 June 2020, and 14 April 2021. Various demographic, laboratory, and clinical data were collected to calculate several EWSs and determine their efficacy. For all 3608 patients, five EWSs were calculated (MEWS, NEWS, NEWS2, REMS, and qSOFA). Model discrimination performance was tested using sensitivity, specificity, and positive and negative predictive values. C statistic, representing the area under the receiver operating characteristic (ROC) curve, was used for the overall assessment of the predictive model. Results: Among the evaluated prediction scores for 3068 patients with COVID-19, REMS demonstrated the highest diagnostic performance with the sensitivity, PPV, specificity, and NPV of 72.1%, 20.6%, 74.9%, and 96.8%, respectively. In the multivariate logistic regression analysis, aside from REMS, age (p p p p < 0.001) were significant predictors of mortality. Conclusions: Among all evaluated EWSs to predict mortality and ICU admission in COVID-19 patients, the REMS score demonstrated the highest efficacy