Do stone size and impaction influence therapeutic approach to proximal ureteral stones?

Background/Aim. Primary therapeutic approach to lumbar ureteral stones is still contraversial. The aim of the study was to investigate the influence of stone impaction and size on the effectiveness of proximal ureteral stone lithotripsy. Methods. A total of 123 patients with proximal ureteral stones were investigated in this prospective study performed in a 10- month period. The patients were divided into the group I - 86 patients treated with extracorporeal shock wave lithotripsy (ESWL) and the group II - 37 patients treated with 'Swiss' Lithoclast. In the group I, 49 stones (57%) were classified as impacted, while 20 stones (23.3%) were larger than 100 mm2. In the group II, 26 stones (70.3%) were impacted, and 11 stones (29.7%) were larger than 100 mm2. Stones were defined as impacted by the radiographic, echosonographic as well as endoscopic findings in the group II of patients. Stone size was presented in mm2. Chemical composition of stones were almost the same in both groups of the patients. Results. Generally, there was no statistically significant difference in the treatment success between the groups. However, stones larger than 100 mm2 were statistically more successfully treated endoscopically, while there was no statistical difference in the treatment success of impacted stones between these two groups. Conclusion. ESWL can by considered as primary first therapeutic approach in treatment of all proximal ureteral stones except for stones larger than 100 mm2 that should primarily be treated endoscopically

Photon management in semiconductor infrared photodetectors: diffractive and plasmonic antireflective structures

Due to their high specific detectivities and large response speeds, photodetectors based on narrow-bandgap semiconductors like indium-antimonide and mercury cadmium telluride are indispensable for mid- and far-infrared wavelength ranges. Their response is directly proportional to the infrared radiation flux introduced to the detector active area. Thus various photon management techniques are of crucial importance for enhancing their performance. This work analyzes the use of subwavelength nanophotonic structures with antireflective properties. It considers surface-based diffractive optical structure that can be produced by micromachining and nanofabrication. The first part of the consideration is dedicated to all-dielectric subwavelength arrays with 1D and 2D periodicity, which effectively behave as impedance-matching structures with graded effective refractive index. The consideration is then expanded to metal-dielectric structures, especially those belonging to the class of the so-called plasmonic ultra-absorbers. Technologies available in Serbia are then investigated technologies for the fabrication of the dielectric and metaldielectric subwavelength antireflective structures for the infrared, including isotropic and anisotropic etching of surface reliefs and ultrathin-film deposition techniques. It is concluded that diffractive dielectric and plasmonic structures offer a novel degree of freedom in optimization of infrared semiconductor photodetectors

Poli(uretan-siloksani) na bazi hiperrazgranatog poliestra kao umreživača - sinteza i karakterizacija

A series of novel polyurethane crosslinked structures (PUs) was prepared from α,ω-dihydroxy-(ethylene oxide-poly(dimethylsiloxane)-ethylene oxide) (EO-PDMS-EO), 4,4'-methylenediphenyl diisocyanate and Boltorn ® hyperbranched polyester of the third pseudo generation. The hydroxyfunctional hyperbranched aliphatic polyester with 26 end groups was used as a crosslinking agent. In order to improve the compatibility of all the reactants during the synthesis, the PU samples were prepared by two-stage, step-growth polymerization in solution. The content of the soft EO-PDMS-EO segments was varied in the range from 15 to 40 wt. %. The influence of the EO-PDMS-EO content on the swelling behavior, crosslink density, hardness, and the thermal and surface properties of the synthesized PUs was investigated. The structure of the synthesized polyurethanes was confirmed by the presence of specific bands in the Fourier transform infrared spectra. Swelling studies were performed to determine the crosslink density and polyurethane networks with lower EO-PDMS-EO contents had higher crosslink densities. The glass transition temperature of the synthesized PUs, determined by differential scanning calorimetry, slightly increased from 50 to 58°C on decreasing the EO-PDMS-EO content because of the higher crosslink density of the samples. Increasing the EO-PDMS-EO content led to better thermal stability, as was evidenced by the onset temperature of weight loss. The surface of the polyurethane networks became more hydrophobic with increasing EO-PDMS-EO content. The surface morphology of synthesized polyurethanes was analyzed by scanning electron microscopy.U ovom radu prikazana je sinteza, struktura i neka svojstva novih umreženih poliuretana pripremljenih polazeći od α,ω-dihidroksi-(etilenoksid-poli(dimetilsiloksan)-etilenoksid) pretpolimera (EO-PDMS-EO), 4,4'-metilendifenildiizocijanata i Boltorn® hiperrazgranatog poliestra treće pseudo-generacije. Hiperrazgranati hidroksi funkcionalni alifatski poliestar sa 26 krajnjih grupa služio je kao umrežavajući agens pri sintezi poliuretana. U cilju poboljšanja kompatibilnosti reaktanata tokom sinteze, poliuretani su sintetisani dvostepenom polimerizacijom u rastvoru. Sadržaj mekog EO-PDMS-EO segmenta variran je u opsegu od 15 do 40 mas. %. Ispitan je uticaj EO-PDMS-EO sadržaja na ponašanje pri bubrenju, gustinu umrežavanja, tvrdoću, termička i površinska svojstva sintetisanih poliuretana. Struktura sintetisanih poliuretana potvrđena je FTIR spektroskopijom. Ponašanje pri bubrenju je ispitivano kako bi se odredila gustina umrežavanja i pokazano je da poliuretanske mreže sa nižim EO-PDMS-EO sadržajem imaju veću gustinu umrežavanja. Rezultati diferencijalne skenirajuće kalorimetrije pokazali su povećanje temperature ostakljivanja poliuretana od 50 do 58°C sa smanjenjem EO-PDMS-EO sadržaja kao posledicu veće gustine umreženosti uzoraka. Sintetisani poliuretani sa većim sadržajem EO-PDMS-EO segmenata pokazuju bolju termičku stabilnost, što je potvrđeno porastom početne temperature degradacije, određene TG analizom. Hidrofobnost površine poliuretana je rasla sa povećanjem sadržaja EO-PDMS-EO u odgovarajućem uzorku. Površinska morfologija sintetisanih poliuretana je analizirana skenirajućom elektronskom mikroskopijom

Цитотоксични потенцијал естара линолеинске киселине детектованих у одбрамбеним секретима стонога Megaphyllum bosniense и M. unilineatum (Diplopoda: Julida)

Najveći broj stonoga iz klase Diplopoda poseduje hemijsku zaštitu od predatora i/ili patogenih mikroorganizama, koji podrazumeva prisustvo odbrambenih žlezda (ozadena) na trupu čiji se sekreti izbacuju u spoljašnju sredinu preko otvora koji se naziva ozopora. Predstavnici reda Julida su poznati po tome da su najčešće dominantne komponente njihovih odbrambenih sekreta hinoni. Pored hinona, u sekretima ozadena Julida registrovani su i alkoholi, aldehidi, ketoni, fenolna jedinjenja, kao i brojni estri zasićenih i nezasićenih karboksilnih kiselina. Dosadašnja istraživanja su pokazala da su ekstrakti odbrambenih sekreta Julida, kao i pojedinačna jedinjenja koja u njihov sastav ulaze, biološki aktivni prirodni proizvodi, ali njihov citotoksični potencijal nije dovoljno istražen. U ovoj studiji je ispitivan uticaj različitih estara linoleinske kiseline (butil-, pentil-, heksil-, heptil-, oktil-, nonil-, fenetil- i 3- fenilpropil-linoleat) detektovanih u odbrambenim sekretima stonoga Megaphyllum bosniense i M. unilineatum na vijabilnost normalnih (BEAS-2B) i kancerskih (A549) ćelija pluća korišćenjem MTT testa. Svi ispitivani estri su smanjivali vijabilnost ćelija, pri čemu je postojala značajna razlika u odgovoru kancerskih u odnosu na normalne ćelije u slučaju tri estra (heksil-, fenetil- i 3- fenilpropil-linoleat). Iako su estri karboksilnih kiselina poznati kao malo reaktivna jedinjenja, rezultati ove studije pokazuju da predstavnici ove klase hemijskih jedinjenja mogu imati citotoksični potencijal.Највећи број стонога из класе Diplopoda поседује хемијску заштиту од предатора и/или патогених микроорганизама, који подразумева присуство одбрамбених жлезда (озадена) на трупу чији се секрети избацују у спољашњу средину преко отвора који се назива озопора. Представници реда Julida су познати по томе да су најчешће доминантне компоненте њихових одбрамбених секрета хинони. Поред хинона, у секретима озадена Julida регистровани су и алкохоли, алдехиди, кетони, фенолна једињења, као и бројни естри засићених и незасићених карбоксилних киселина. Досадашња истраживања су показала да су екстракти одбрамбених секрета Julida, као и појединачна једињења која у њихов састав улазе, биолошки активни природни производи, али њихов цитотоксични потенцијал није довољно истражен. У овој студији је испитиван утицај различитих естара линолеинске киселине (бутил-, пентил-, хексил-, хептил-, октил-, нонил-, фенетил- и 3- фенилпропил-линолеат) детектованих у одбрамбеним секретима стонога Megaphyllum bosniense и M. unilineatum на вијабилност нормалних (BEAS-2B) и канцeрских (A549) ћелија плућа коришћењем МТТ теста. Сви испитивани естри су смањивали вијабилност ћелија, при чему је постојала значајна разлика у одговору канцерских у односу на нормалне ћелије у случају три естра (хексил-, фенетил- и 3- фенилпропил-линолеат). Иако су естри карбоксилних киселина познати као мало реактивна једињења, резултати ове студије показују да представници ове класе хемијских једињења могу имати цитотоксични потенцијал.Knjiga sažetaka: Treći Kongres biologa Srbije, Zlatibor, Srbija 21 - 25. 9. 2022

Bioaccumulation of metallic trace elements and antioxidant enzyme activities in Apfelbeckia insculpta (L. Koch, 1867) (Diplopoda: Callipodida) from the cave Hadži-Prodanova Pećina (Serbia)

The concentration of 10 metallic trace elements or MTE (Cu, Fe, Zn, Mn, As, Hg, Pb, Cd, Ni, and Cr) was measured in specimens of the troglophilic millipede Apfelbeckia insculpta (L. Koch, 1867) and sediment of the cave Hadži-Prodanova Pećina in western Serbia. Some MTE, like Fe and Mn, displayed much higher concentrations compared to other elements, both in the sediment and in the body of A. insculpta. On the other hand, estimation of the bioaccumulation factor (BAF) in both males and females of A. insculpta showed values greater than 1 for xenobiotic elements compared to those that are essential. In addition to chemical analyses, we examined the activities of antioxidant enzymes (SOD, CAT, GPX, and GR) and the phase II biotransformation enzyme GST, as well as the content of –SH groups, in the body of A. insculpta. Activities of two (GR and GST) out of the five tested enzymes showed significant differences between the sexes. These results represent the first comprehensive report of antioxidant enzymes in myriapods. The noted differences in the investigated MTE and enzyme activities between the sexes of A. insculpta most likely reflect different metabolic activities and responses to environmental conditions in males and females.International Journal of Speleology (2017), 46(1): 99-10

Citotoksični potencijal ekstrakata i odabranih estara iz odbrambenih sekreta vrsta Megahphyllum bosniense i M. unilineatum (Diplopoda: julida) prema ćelijama raka debelog creva

Ciljevi ove studije bili su: 1) ispitivanje citotoksičnog potencijala različitih estara linoleinske kiseline (butil-, pentil-, heksil-, heptil-, oktil-, nonil-, fentil- i 3-fenilpropil- linoleat) detektovanih u odbrambenim sekretima dve vrsta stonoga iz reda Julida - Megaphyllum unillineatum (C. L. Koch, 1838) i M. bosniense (Verrhoeff, 1897) na vijabilnost ćelija raka debelog creva (SW480) i 2) analiza vijabilnost SW480 ćelija nakon tretiranja ekstraktima odbrambenih sekreta pomenutih vrsta

Conjugated linoleic acids in poultry nutrition

Конјуговане линолне киселине (CLA) су позициони и геометријски изомери есенцијалне линолне масне киселине. У исхрани људи CLA имају антиканцерогено, антиатерогено, имуномодулаторно и деловање против гојазности. Такође повољно утичу на имуни систем, метаболизам костију и односе ткива у телу. Највеће количине CLА налазе се у месу преживара као последица активности бактерија (Butirovibrio fibrisolvens) које изомеризују линолну киселину. Садржај CLА не разликује се само између врста меса (говеђе, овчије, свињско, живинско), већ и између различитих ткива исте животињске врсте. Исхрана има значајан утицај на садржај CLА у ткивима животиња. Бројне студије су показале да се садржај CLА може повећати како код преживара, тако и код моногастричних животиња. Код моногастричних животиња садржај CLА може да се повећа њеном употребом у исхрани или додавањем у оброк животиња њених прекурсора (вакценска киселина, омега-7 масна киселина). У исхрани живине, препарати CLА додају се најчешће у количини до 2%, што повећава садржај CLА у месу и при том не утиче негативно на производне резултате и параметре квалитета меса. Запажено је да повећан садржај CLА у месу повoљно утиче на његову оксидативну стабилност. Основни циљ употребе CLА у исхрани живине је повећање садржаја CLА у месу, чиме може да се добије производ посебног квалитета (функционална храна).Conjugated linoleic acid (CLA) are positional and geometric isomers of essential linoleic fatty acid. CLA in the human diet have anti-carcinogenic, anti-atherogenic, immunomodulatory and anti-obesity functions. Also, they have a beneficial effects on the immune system, bone metabolism and interrelation of tissues in the body. The highest amounts of CLA have been found in meat of ruminant as a result of bacterial activity (Butirovibrio fibrisolvens) which have the capacity to isomerise linoleic acid. The content of CLA is not different only between various types of meat (beef, sheep, pork, poultry) but also between different tissues of the same animal species. Nutrition has a significant impact on the content of CLA in animal tissue. Numerous studies have shown that content of CLA can be increased in the ruminants such as in monogastric animals. In monogastric animals the content of CLA can be increased by their use in food or by adding in animal meal their precursors (vaccenic acid, an omega-7 fatty acid). In poultry nutrition CLA preparations are usually added in an amount up to 2%, which increases the CLA content in meat without any adverse effect on the performance and meat quality parameters. It was observed that increased content of CLA in meat favorably affect its oxidative stability. The main objective of the use of CLA in poultry nutrition is to increase the CLA content in meat in order to obtain a product of a special quality (functional food)

Antioxidant activity relationship of phenolic compounds in Hypericum perforatum L.

<p>Abstract</p> <p>Background</p> <p>The St John's Wort (<it>Hypericum perforatum</it>; Clusiaceae) has been used in traditional and modern medicine for a long time due to its high content of biologically active phenolics. The purpose of this work was to develop a method for their fractionation and identification, and to determine the most active antioxidant compounds in plant extract.</p> <p>Results</p> <p>An LC-MS method which enables fast qualitative and semiquantitative analysis was developed. The composition determined is in agreement with the previous results, where 6 flavonoids, 4 naphthodianthrones and 4 phloroglucinols have been identified. Significant antioxidant activity was determined for most of the fractions by DPPH assay (the lowest IC₅₀of 0.52 μg/ml), NO scavenging (6.11 μg/ml), superoxide scavenging (1.86 μg/ml), lipid peroxidation (0.0079 μg/ml) and FRAP (the highest reduction capacity of 104 mg Fe equivalents/g) assays.</p> <p>Conclusion</p> <p>LC-MS technique has been successfully applied for a quick separation and identification of the major components of <it>H. perforatum </it>fractions. Majority of the fractions analyzed have expressed a very high antioxidative activity when compared to synthetic antioxidants. The antioxidant activity could be attributed to flavonoids and phenolic acids, while phloroglucinols and naphthodianthrones showed no significant activity. It is demonstrated that it is possible to obtain, by fractionation, <it>H. perforatum </it>preparations with significantly increased phloroglucinols-to-naphthodianthrones ratio (up to 95:5).</p

Prevention of illegal conduct in business insurance in Serbia

The paper deals with the specificities concerning prevention of unlawful behavior within the insurance industry in Serbia. The work covers modern forms of state intervention, as well as types, trends and basic aspects of the prevention of unlawful behavior in the insurance industry. We pointed out two main aspects of prevention in the field of insurance. These are general deterrence and specific deterrence. The term general deterrence of unlawful conduct in the insurance industry refers to a system of measures, or sanctions, which aim to deter potential perpetrators to take actions of fraud in insurance activities. Specific deterrence means preventing the illegal behavior of individuals or groups in the field of insurance. In addition, it especially points to the extreme complexity of the process of detection, as well as the great social threat which unlawful activities of organized crime groups pose, especially in conjunction with individuals who are willing, from selfish interest, to cooperate with the organizer of the criminal group through an unlawful exercise of their own professional tasks