Influence of the application of ionic activators based on d-metals Zn, Co, Cu, Ni, Mo and laser radiation on the energy efficiency of hydrogen generation from alkaline electrolysis.

Rast životnog standarda sve brže rastuće svetske populacije zahteva veliki napredak u snabdevanju energijom i povećanom energetskom efikasnošću kako bi se zadovoljile sve veće potrebe modernog društva. Već decenijama odgovori na ove zahteve pronalaze se u obnovljivim izvorima energije čiji je cilj da budu održivi i ekonomski konkurentni sa tehnologijama zasnovanim na korišćenju fosilnih goriva. Kako bi obnovljivi izvori u budućnosti bili u potpunosti osnov održivog razvoja i snabdevnja energijom neophodno je pronaći najpogodniji način za skladištenje i transport energije dobijene iz ovih izvora, sve u cilju kontinuiranog snabdevanja energijom čak i u slučajevima kada obnovljivi izvori nisu dostupni. Vodonik je trenutno najbolji kandidat, kao medijuma koji zadovoljava sve uslove za ovakvu manipulaciju energijom i koji se uklapa u buduće energetske koncepte...The growing standard of living and rising of world population requires increasing demands for energy supply and its efficiency to meet the needs of modern society. For decades, answers to these requirements are found in renewable energy sources that aim to be sustainable and economically competitive with fossil-fueled technologies. In order to make renewable sources in the future the basis of sustainable development and energy supply, it is necessary to find the most suitable way for storing and transporting energy from these sources, with the aim of continuously supplying energy even in cases where renewable sources are not available. Hydrogen is currently the best candidate as an energy medium, which meets all the requirements for such energy manipulation and fits into future energy concepts..

Development of low carbon and energy-efficient geopolymer-based paving blocks

The development of energy-efficient and low-carbon geopolymer-based paving blocks made from waste, as an environmental-friendly material, was evaluated. Ground concrete (GC) and solid brick (SB) powder, as the representatives of construction and demolition waste (C&DW), with the addition of fly ash (FA) and silica fume (SF), were used. Waste samples were characterized in terms of surface functional groups and radioactivity. The FT-IR spectra showed the required amorphous or semi-crystalline alumino-silicate structure. The gamma spectrometry confirmed waste samples' radiological safety. Hardened geopolymer samples were subjected to physical-mechanical investigation comprising of density, water content, compressive and flexural strengths determination. Based on strength characteristics, the three best prototype mixtures were selected and subjected to further compressive strength determination and durability assessment. Prototype sample SBFASFp1, with a compressive strength of 18.7 MPa, was shown the highest value of all samples, almost the same as the corresponding SBFASF1 sample. Freeze-thaw and the subsequent carbonation tests, as durability indicators, showed that the SBFASF1 sample had the slightest strength decrease, making it most durable in these conditions. These satisfactory test results showed the favorable effects of alternatives to cementitious materials, encouraging their utilization and contributing to the sustainability of the construction sector

Analysis of loss of heterozygosity of the tumor suppressor genes p53 and BRCA1 in ovarial carcinomas

Background/aim: Among the genes involved in ovarian carcinogenesis, there has been increased interest in tumor-suppressor genes p53 and BRCA1. Both of the genes make control of cell cycle, DNA repair and apoptosis. The p53 is a "genome guardian" inactivated in more than 50% of human cancers, while BRCA1 mutations are found mostly in breast and ovarian cancer. The aim of this investigation was to establish the frequency of loss of heterozygosity (LOH) in the regions of the genes p53 and BRCA1 in ovarian carcinomas, and to analyze the association of LOH with the disease stage and prognosis. Methods. We analyzed 20 patients with a confirmed diagnosis of epithelilal ovarian carcinoma. DNA for molecular-genetic analysis was extracted from the tumor tissue and blood as normal tissue of each person. Microsatellite markers of the regions of genes p53 and BRCA1 were amplified by PCR method. The determination of allelic status of microsatellites and detection of LOH was performed after PAA gel electroforesis. Results. Both of the analyzed microsatellite markers were informative in 13/20 (65%) cases. In the region of gene p53, LOH was established in 4/13 (30.7%) tumors. One of them had histological gradus G1, one had gradus G2, and two of them had gradus G3, while all were with the International Federation of Gynecology and Obstetrics (FIGO) IIIc stage. In the region of gene BRCA1, LOH was detected in 5/13 (38.5%) tumors. Four of them had histological gradus G2, and one had gradus G3, while by the (FIGO) classification one was with stage Ib, one was with stage IIIb, while the three were with stage IIIc. LOH in both of the analyzed regions was detected in one tumor (7.7%), with histological gradus G3 and the FIGO IIIc stage. Conclusion. The frequency of LOH in epthelial ovarian carcinomas was 30.7% and 38.5% for p53 and BRCA1 gene regions, respectively. Most of tumors with LOH had histological gradus G2 or G3, and the clinical FIGO stage IIIc, suggesting the association of this occurrence with a later phase of the disease

Contraceptive Choices and Sexual Behavior in Students

Godine 1997. provedeno je istraživanje na manjem uzorku studentica Sveučilišta u Zagrebu (N = l 14). Cilj istraživanja bio je ispitati koja sredstva i metode kontracepcije studentice koriste, koji su im izvori informacija o kontracepciji te kakva je povezanost nekih socio-kulturnih i ekonomskih prediktora s izborom i (ne)korištenjem kontracepcije. Dobiveni rezultati upućuju na rijetko korištenje kontracepcije kao zaštite od neželjene trudnoće i još rjeđe kao zaštite od spolnih bolesti.In 1997 a research was carried out on 114 female students at the University of Zagreb. The goal of the research was to identify respondents plural\u27 contraceptive choices , sources of information about contraception and the relation between some socio-cultural, economic sectors and contraception choices. The results indicated low levels of sexual responsibility among students, i.e. serious lack of consistent protection against unwanted pregnancy and, specially, against sexually transmitted deseases

Energetska tranzicija i vodonična evolucija

The escalating concerns over climate changes and environmental disturbances resulting from anthropogenic influence have propelled the scientific community to seek efficient models for the energy transition. Hydrogen emerges as a promising energy carrier with the potential to replace fossil fuels and mitigate global warming, a pressing threat to life on Earth. This research paper primarily focuses on the electrolytic production of hydrogen, deemed the environmentally acceptable method for this purpose. The central emphasis lies in enhancing the electrodes utilized in this process to elevate the significance of the Hydrogen Evolution Reaction (HER). By improving HER, a pivotal step in the hydrogen production process, the trajectory of civilization's evolution can be positively influenced.Sve veća zabrinutost zbog klimatskih promena i ekoloških poremećaja koji su rezultat antropogenog uticaja naterali su naučnu zajednicu da traži efikasne modele za energetsku tranziciju. Vodonik se pojavljuje kao perspektivan nosilac energije sa potencijalom da zameni fosilna goriva i ublaži globalno zagrevanje, goruću pretnju životu na Zemlji. Ovaj istraživački rad se prvenstveno fokusira na elektrolitičku proizvodnju vodonika, koja se smatra ekološki prihvatljivom metodom za ovu svrhu. Centralni naglasak je na poboljšanju elektroda koje se koriste u ovom procesu kako bi se podigao značaj reakcije evolucije vodonika (HER). Poboljšanjem HER, ključnog koraka u procesu proizvodnje vodonika, može se pozitivno uticati na putanju evolucije civilizacije

Razvoj hromatografskih metoda za analizu sulfametoksazola, trimetoprima, njihovih degradacionih proizvoda i konzervanasa u sirupu

In this paper the experimental conditions for optimal reversed-phase liquid chromatographic (RP-HPLC) determination of sulfamethoxazole, trimethoprim and preservatives, as well as degradation products of sulfamethoxazole and trimethoprim in syrup were defined. The determination of active compounds and preservatives was carried out on Zorbax Eclipse XDB-C18, 150 mm × 4.6 mm, 5 μm particle size column, mobile phase flow rate was 1.5 mL min-1, and detection at 235 nm for the active compounds and 254 nm for preservatives. Mobile phase A consisted of 150 mL of acetonitrile, 850 mL of water and 1 mL of triethanolamine (pH 5.90 adjusted with diluted acetic acid), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. For the determination of degradation products Zorbax Eclipse Plus C18, 100 mm x 4.6 mm, 3.5 μm particle size column was used, the mobile phase flow rate was 0.5 mL min-1 and detection at 210 nm for 3,4,5-trimethoxybenzoic acid and 254 nm for sulfanilic acid and sulfanilamide. Mobile phase A was 50 mM potassium dihydrogenphosphate (pH 5.60 adjusted with a 0.5 mol L-1 potassium hydroxide), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. Through the validation of the developed methods their efficiency and reliability is confirmed and consequently the adequacy for the routine control.U ovom radu prikazano je definisanje eksperimentalnih uslova i optimizacija metoda reverzno-fazne tečne hromatografije (RP-HPLC) za određivanje sulfametoksazola, trimetoprima i konzervanasa, odnosno degradacionih proizvoda sulfametoksazola i trimetoprima u sirupu. Određivanje sadržaja aktivnih komponenti i konzervanasa vršeno je na koloni Zorbax Eclipse XDB-C18, 150 mm × 4,6 mm, 5 μm veličine čestica, protok mobilne faze bio je 1,5 mL min-1, dok je detekcija vršena na 235 nm za aktivne komponente i 254 nm za konzervanse. Mobilna faza A sastojala se od smeše 150 mL acetonitrila, 850 mL vode i 1 mL trietanolamina (pH 5,9 podešen razblaženom sirćetnom kiselinom), a kao mobilna faza B korišćen je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. Određivanje sadržaja degradacionih proizvoda vršeno je na koloni Zorbax Eclipse Plus-C18, 100 mm × 4,6 mm, 3,5 μm veličine čestica, uz protok mobilne faze od 0,5 mL min-1 i detekciju na 210 nm za 3,4,5-trimetoksibenzojevu kiselinu i 254 nm za sulfanilnu kiselinu i sulfanilamid. Mobilna faza A bila je 50 mM kalijum-dihidrogenfosfat (pH 5,60 podešen sa 0,5 mol L-1 kalijum-hidroksidom), a mobilna faza B bio je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. Validacijom postavljenih metoda potvrđeno je da su efikasne i pouzdane, i kao takve pogodne za rutinsku kontrolu

First evidence of the P-glycoprotein gene expression and multixenobiotic resistance modulation in earthworm

Multixenobiotic resistance (MXR) is an important mechanism of cellular efflux mediated by ATP binding cassette (ABC) transporters that bind and actively remove toxic substrates from the cell. This study was the first to identify ABC transporter P-glycoprotein (P-gp/ABCB1) as a representative of the MXR phenotype in earthworm (Eisenia fetida). The identified partial cDNA sequence of ABCB1 overlapped with ABCB1 homologues of other organisms from 58.5 % to 72.5 %. We also studied the effect of five modulators (verapamil, cyclosporine A, MK571, probenecid, and orthovanadate) on the earthworm’s MXR activity by measuring the accumulation of model substrates rhodamine B and rhodamine 123 in whole body tissue of the adult earthworm. MK571, orthovanadate, and verapamil significantly inhibited MXR activity, and rhodamine 123 turned out to better reflect MXR activity in that species than rhodamine B. Our results show that E. fetida can serve well as a test organism for environmental pollutants that inhibit MXR activity

NPM1 gene mutations in children with Myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are rare in children and only a few studies have analyzed their molecular mechanisms. The NPM1 gene encodes for nucleophosmin (NPM) which regulates hematopoiesis. Mutations in exon 12 of the NPM1 cause the nucleophosmin cytoplasmic dislocation and disrupt its functions. We have analyzed mutations of the NPM1 gene in archival bone marrow samples from 17 children with MDS and detected, in one patient, transition C to T in codon 293. To the best of our knowledge, this is the first analysis of NPM1 mutations in childhood MDS and the very first missense mutation of the NPM1 gene reported so far