In vitro antioxidant activity of honeydew and multifloral types of honey from Serbia

Antioxidant properties of fifteen multifloral and honeydew types of honey from Serbia were assessed by determination of ferric-reducing antioxidant power (FRAP assay) and 2,2- diphenyl-1-picrylhydrazyl free radical scavenging ability (DPPH assay), with respect to their total polyphenol content and colour intensity. The results of this study showed that total polyphenol content, antioxidant activity and colour intensity varied widely among different samples, even within the same type of honey. All investigated parameters were strongly dependent on geographic origin of samples, further emphasizing the importance of their detailed chemical characterisation. In general, polyphenolic content in investigated samples of honey, expressed as catechin equivalents, ranged from 480.2 to 1861.1 mg/kg. The ferric-reducing antioxidant power of honey tended to be lower in brighter and higher in darker samples, varying between 489.6 and 3089.8 μmol Fe(II) per 100 g of honey. The correlation between the colour and antioxidant activity never reached statistical significance in the case of honeydew type of honey, which was opposed to a trend observed in the case of multifloral honey. [Projekat Ministarstva nauke Republike Srbije, br. 143012

The preparation and characterizationof phosphoroustungsten bronzes doped with lithium, magnesium and europium ions.

Heteropoli kiseline ĉija je opšta formula H3+xAM12040∙nH20 (x=0-1; A=P, Si, B, As, Ge; M=Mo, W; n=30-6) imaju poseban znaĉaj kao novi materijali sa velikim provodljivostima. MeĊu njima posebnu paţnju zasluţuje 12-volframfosforna (29-WPA) kiselina. U ovom radu prikazana je studija o kalcinaciji/dehidrataciji i strukturnim modifikacijama WPA hidrata od sobne temperature do 1150 0C. Mi smo takoĊe ispitivali prateće modifikacije protonskih vrsta tokom procesa dehidratacije kao i sintezu fosforvolframove bronze i njihove polimorfne transformacije. Dizajniranje materijala saglasno teorijski dobro definisanim oĉekivanjima, ima izuzetan znaĉaj za preciznije definisanje strukture materijala i uslove njihove sinteze, koji omogućuju organizovanje takve strukture na predvidiv naĉin. Samo dizajniranje strukture na svim nivoima od osnovnog, saglasno našim eksperimentalnim i teorijskim modelnim istraţivanjima daje rezultate koji pokazuju izuzetnu meĊusobnu saglasnost teorijskih oĉekivanja i eksperimentalnih rezultata. U ovom radu je pokazano kako sprej piroliza sa ultrazvuĉnom pobudom moţe biti iskorišćena za dobijanje sfernih prahova fosforvolframovih bronzi dopiranih jonima litijuma, magnezijuma i europijuma, polazeći odH3PW12O40∙29H2O (WPA) kao prekursora. Ovi prahovi imaju nanostrukturni dizajn, sa srednjom veliĉinom ĉestice od 1 μm, koja se sastoji iz subĉestica veliĉine od 30 do 80 nm.Heteropolyacids, with a general formula ofH3+xAM12040∙nH20 (x=0-1; A=P, Si, B, As, Ge;M=Mo, W; n=30-6) are of special interest as newmaterials because of their high conductivities. Among them special attention deserves the 12-tungstophosphoric (29-WPA) acid. In this paper we report a study of the calcination/dehydration and structural modification of WPA hydratesfrom room temperature to 11500C. We alsoinvestigated the accompanying modifications of theprotonic species during the dehydration process aswell as the synthesis of phosphorus-tungsten bronzesand their polymorphous transformations. Designing of materials according to theoretically well determined predictions is of exceptional importance for more precise definition of materials structures, and synthesis conditions which provide organizationof such structures in a clear and predictable way. Only designing of structures at all levels from the basic ones according to our research and theoretical models, gives results that show excellent agreement between theoretical expectations and experimental observations. In this paper it is shown how the ultrasonic spray pyrolysis can beused to obtain fine spherical powder particles of phosphoroustungsten bronzes doped with lithium, magnesium and europium ions, from the feeding solution WPA-29 (H3PW12O40∙29H2O). This powder has nanostructured design with average particle size1 μm, and subparticles 30-80 nm

Мали утицај калцијумом допиране фосфат волфрамове бронзе на динамику Бригс−Раушер реакције

The Briggs-Rauscher (BR) oscillatory reaction is the oxidation of malonic acid in the presence of hydrogen peroxide and iodate in the acidic environment, which is catalyzed by ions of manganese. This reaction is very sensitive to the presence of additives. In this paper, the BR reaction has been used to investigate the phosphate tungsten bronze as well as calcium doped tungsten bronze, obtained by thermal treatment. The addition (0.01-0.08 g) of phosphate tungsten bronze and calcium doped phosphate tungsten bronze has a different effect on the dynamics of the Briggs-Rauscher reaction. In the case of the addition of phosphate tungsten bronze in the Briggs-Rauscher reaction, the linear dependence of the length of the oscillatory period on the mass of the added bronze was obtained, while in the case of addition of calcium doped phosphate tungsten bronze, the oscillatory period does not significantly change with an increase of added mass. The mechanism of calcium doped and undoped phosphate tungsten bronze action in BR reaction is probably adsorptive, and it will be the subject of future work.Бригс−Раушер (БР) осцилаторна реакција је реакција оксидације малонске киселине у присуству водоник-пероксида и јодата у киселој средини, која је катализована јонима мангана. Ова реакција је веома осетљива на присуство адитива. У овом раду, БР реакција је коришћена за испитивање фосфат волфрамове бронзе, као и калицијумом допиране фосфат волфрамове бронзе, које су добијене термичким третманом. Додатак (0,01−0,11 g) фосфат волфрамове бронзе и калцијумом допиране фосфат волфрамове бронзе има различит утицај на динамику Бригс−Раушер реакције. У случају додатка фосфат волфрамове бронзе у Бригс−Раушер реакцију, добијена је линеарна зависност дужине осцилаторног периода од масе додате бронзе, док у случају додатка калцијумом допиране фосфат волфрамове бронзе, осцилаторни период се не мења значајно са повећањем масе додате бронзе. Механизам деловања калцијумом допиране и недопиране фосфат волфрамове бронзе на БР реакцију је вероватно адсорпциони процес и биће предмет будућих истраживања

Effects of NPK rates and ratio on sugar beet yield and quality

Small plot trials were conducted at the experimental fields of the Institute Tamiš, Pančevo, on the lime chernozem soil type over the period 1998- 2003. There were 19 variants in the trial in addition to the control. The NPK amounts ranged from 50 to 130 kg/ha and were used in various ratios. The highest average sugar beet yield was obtained using 100 kg/ha of NPK (59,97 t/ha). The increase amounted to 47,9% compared with the control variant. The average sugar content in the root ranged from 13,67 (N130P50K50) to 14,45% (N0P0K100) and sugar use from 11,05 (N130P50K50) to 12,09% (N50P100K100). The highest average consumable sugar yield was registered using the following fertilizer variant N100 P100K100 (6.98 t/ha) and N100P100K50 (6.81 t/ha). Root yield and consumable sugar yield were greatly affected by the humidity during the sugar beet vegetation period

Therapeutic efficacy of connective tissue autotransplants with periosteum and platelet rich plasma in the management of gingival recession

Background/Aim. Gingival recession progression in clinical practaice has influenced the development of various surgical procedures and techniques for solving esthetic imperfections and subjective difficulties coused by gingival recession. The aim of this study was to verify efficacy of surgical procedures and to compare both of surgical procedures through the keratinized tissue width. Methods. The study included 20 teeth with gingival recesion, Müller class I and II. Ten teeth with gingival recession were treated with connective tissue autotransplants with periosteum in combination with coronary guided surgical flap (CTG group). On the contralateral side 10 teeth with gingival recession were treated with the same surgical procedures but in combination with platelet-rich plasma (CTGPRP group). We measured the keratinized tissue width. For statistical significance we used the Student's t-test. Results. The study reveled a statistical significance in reducing vertical deepress of recession by both used treatments. Root deepness in CTG and CTG-PRP group was 90% and 93.5%, respectively. With both surgical techniques we achieved larger zone of keratinized gingiva but with a wide zone of keratinized tissue in CTG - the PRP group. Conclusion. The concept regeneration technique with PRP and with the stimulating influence of platele activated growth factors results in the regeneration of deep periodontal tissue as an important prerequisite for the successful treatment of gingival recession

Korelacija morfoloških i proizvodnih osobina društava medonosne pčele sa područja Srbije

State of mutual or reciprocal relationship between traits is determined by the correlation coefficients. Correlation of morphological and production traits was determined in two generations of honey bee colonies. In the first generation, mother queen bees were studied, and in the second generation, their offspring. The study of one generation lasted two years. Morphological traits were determined in the beginning of the study and production traits were determined in the spring and autumn inspections of every year. In the first generation, the positive and mostly high correlation between morphological traits, and honey yield and hygienic behavior was determined. Correlation of morphological traits, colony strength and food supplies per colony ranged from highly positive to slightly negative values. It was found that there was a high correlation between some production traits (colony strength in the spring and autumn inspections and honey yield per colony). In the analysis of offspring (second generation), most traits that were positively correlated in mother generation now, also, showed a similar relationship. The only difference, in contrast to mother generation, was that, for most traits, the intensity of interaction increased.Stanje uzajamne ili recipročne povezanosti jedne osobine od druge utvrđuje se na osnovu koeficijenta korelacije. Korelacija morfoloških i proizvodnih osobina utvrđivana je kroz dve generacije društava medonosne pčele. U prvoj generaciji praćene su majke matice, a u drugoj njihovo potomstvo. Ispitivanje po jednoj generaciji trajalo je dve godine. Morfološke osobine su utvrđene na početku praćenja generacija, a proizvodne na prolećnom i jesenjem pregledu svake godine. U prvoj generaciji utvrđena je pozitivna i mahom visoka korelacija između morfoloških osobina, prinosa meda i higijenskog ponašanja. Stepen korelacije morfoloških osobina, snage društva i zaliha hrane po društvu bio je od visoko pozitivne do slabo negativne vrednosti. Ustanovljeno je da postoji i visok stepen korelacije između pojedinih proizvodnih osobina (snaga društava na prolećnom i jesenjem pregledu i prinosa meda po društvu). Prilikom testiranja potomstva (II generacija) većina osobina koje su bile u pozitivnoj korelaciji kod roditelja i sada su pokazivala uzajamni odnos. Jedina razlika u odnosu na roditelje je u tome da se, za većinu osobina, intezitet međusobnog uticaja povećao

Synthesis of BCP and BCP/PLGA biomaterials by ultrasonic spray pyrolysis

The most significant mass part of the bony tissue consists of calcium phosphate ceramics. This paper describes method of obtaining fine particles of biphasic calcium phosphate (BCP) as well as fine particles of biphasic calcium phosphate covered by polymer, poly-lactide-co-glycolide (BCP/PLGA), by ultrasonic spray pyrolysis. Methods used for characterization of obtained particles of BCP and BCP/PLGA are Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM) techniques.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Characterization of the sludge generated during the processing of iron ore in Omarska mine

In present paper there were characterized sludge samples generated as an overflow during the processing of iron ore from Omarska mine (Bosnia and Herzegovina). With the aim to improve the utilization of minerals, we are carrying out research into the possibility of selective flocculation of limonite from the sludge. The first and very important step in this research is the characterization of sludge. In order to determine the present mineral phases and their chemical compositions, it was performed XRPD, FTIR and SEM-EDS analysis. The XRPD results showed that sludge samples are composed of major goethite and quartz, less clay minerals, and minor magnetite and todorokite. The FTIR and SEM-EDS analysis are in very good agreement and confirms the results obtained by XRPD method

Проучавања флокулације узорка природног кварца у присуству анјонског полиакриламида

The waste sludge generated during processing of iron ore in the Omarska mine (The Republic of Srpska, Bosnia and Herzegovina) is fine-grained (<15μm), containing relatively high concentrations of iron, and quartz as its major impurity. The flocculation behaviour of the primary natural raw “quartz” sample from Omarska mine was studied in the present paper. This sample is composed of major quartz which dominates over minor contents of clay minerals and feldspars, and contain 92.9% of SiO2. Particle size distribution analysis confirm that it is present as fine and ultra-fine particles. The zeta potential of quartz depends on pH value. Settling experiments were performed by using three different dispersants (Na-hexamethaphosphate, Na-pyrophosphate and Na-silicate), and anionic polyacrylamide as flocculants. The best results were achieved with Na-hexametaphosphate (1000 g/t) and anionic polyacrylamide A 100. The effect of a flocculant on the settling rate depends on solid concentration. Settling rates increase significantly with the increase of the liquid component in both cases (natural settling and hindered settling by addition of a flocculant).Отпадни муљ који настаје у процесу припреме жељезне руде у Руднику Омарска (Република Српска, БиХ) је фине гранулације (< 15 μm), садржи релативно висок проценат жељеза и кварц као главну нечистоћу. У овом раду је представљено истраживање понашања у процесу флокулације ровног природног узорка кварца из Рудника Омарска. Узорак се састоји од кварца који доминира, уз присутност минерала глине и фелдспата, са садржајем SiO2 од 92,9%. Гранулометријска анализа је показала да се ради о финим и ултрафиним честицама. Зета-потенцијал зависи од pH вриједности. Експерименти таложења су вршени уз присуство три дисперзанта (Na-хексаметафосфат, Na-пирофосфат и Na-силикат и анјонског полиакриламида као флокуланта. Најбољи резултати су постигнути са Na-хексаметафосфатом (1000 g/t) и анјонским полиакриламидом А 100. Утицај флокуланта на брзину таложења зависи од концентрације чврсте супстанце. Брзина таложења значајно расте са разрјеђењем система у оба случаја (природно таложење италожење у присуству флокуланта)