Pranje domaće vune u Hrvatskoj i utjecaj na okoliš

Wool and wastewaters from scouring can be a mixed blessing - a useful technological raw material or an environmental problem. If wool is scoured with no control, as the case most often is in Croatia, the wastewater released could endanger the environmental stability of the existing water systems. Since the interest has been growing recently for processing domestic wool, which also presents a considerable hazard of polluting water because of unskilled scouring and uncontrolled wastewater release into the natural water flows, we have organized investigations aimed at determining potentially dangerous ecological loads on the Croatian water systems, caused by scouring domestic wool. The results obtained indicate that improper disposal of the wool and/or uncontrolled release of wastewater from scouring present a considerable environmental hazard. We have concluded that impacts on the environment of scouring domestic wool in Croatia are the same as impacts on the environment obtained by normal functioning of a town of 1700_2000 inhabitants.Vuna i otpadne vode od pranja vune mogu biti korisna tehnološka sirovina ili su pak ekološki problem. Ukoliko se vuna nekontrolirano pere, kao što je to najčešće slučaj u Hrvatskoj, ispuštene otpadne vode mogu ugroziti prirodnu ekološku stabilnost postojećih vodenih sustava. S obzirom da je u posljednje vrijeme povećano zanimanje za preradu domaće vune, a time i opasnost od onečišćenja voda zbog nestručnog pranja vune i nekontroliranog ispuštanja otpadne vode od pranja vune u prirodne vodotokove svrha ovog rada bila je odrediti potencijalno moguće ekološko opterećenje vodenih sustava Hrvatske uzrokovano pranjem domaće vune. Rezultati istraživanja pokazuju da nekontrolirano odlaganje vune i/ili otpadne vode od pranja domaće vune u Hrvatskoj predstavlja značajnu opasnost za okoliš, koja je ekvivalentna onečišćenju koje nastaje normalnim funkcioniranjem grada s 1700 do 2000 stanovnika

MAAT system design – weight model of very large lighter-than-air vehicle

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.The main objective of this paper is to provide a realistic weight model, based on the physical-mathematical foundations, for the design of the new very large lighter-than-air vehicle, called Multibody Advanced Airship for Transport (MAAT), the ongoing European FP7 project, which is currently under intensive research and development activities. The Modeling and Simulation (M&S) principles, aided with simulations and visualization tools, have been extensively used, as the key enablers to combine, manage and structure such highly complex engineering process, which emerged as a natural integration mechanism and evidence provider of the encountered complexity, successfully encompassing the MAAT multidisciplinary design requirements. The authors experience, in solving the M&S problems, gained within the European R&D projects, was efficiently reused, where the use of such software technologies have been successfully demonstrated, and today, further applied for the new generation transportations solutions, as envisaged by MAAT, especially addressing the best practices in taking advantage of the variety of multi-physics software and their related analysis tools. The MAAT system is envisaged to be composed of two airships: the Cruiser, which stays at a constant altitude of 16 km, travelling horizontally; and the Feeder, which acts like an elevator system connecting the Cruiser to the ground. In this paper, the proposed weight model is similar to the typical one applied in the aircraft design process. The main difference is primarily the airship teardrop shape, which is commonly applied for the currently produced airships. The main challenge is that MAAT has a very large shape, which has required the introduction of new elements and references, as being presented in this work. The achieved results show that MAAT can be realized, by taking into account the significant weight estimated for such aircrafts, to be for the Cruiser about 533 tons, while the Feeder weight is about 12 tons. As highlighted before, the MAAT design is still under intensive developments, and thus, it is expected that in the coming years, by taking into account the new emerging technological solutions, the lightening of such aircrafts structure is inevitable. In addition, the authors plans are to further investigate new materials and their related applications, in order to improve the structural part of the MAAT system, as one of the essential parts in such new transportation system, expected to become the reality in the forthcoming future.cf201

A Compact Multiphoton 3D Imaging System for Recording Fast Neuronal Activity

We constructed a simple and compact imaging system designed specifically for the recording of fast neuronal activity in a 3D volume. The system uses an Yb:KYW femtosecond laser we designed for use with acousto-optic deflection. An integrated two-axis acousto-optic deflector, driven by digitally synthesized signals, can target locations in three dimensions. Data acquisition and the control of scanning are performed by a LeCroy digital oscilloscope. The total cost of construction was one order of magnitude lower than that of a typical Ti:sapphire system. The entire imaging apparatus, including the laser, fits comfortably onto a small rig for electrophysiology. Despite the low cost and simplicity, the convergence of several new technologies allowed us to achieve the following capabilities: i) full-frame acquisition at video rates suitable for patch clamping; ii) random access in under ten microseconds with dwelling ability in the nominal focal plane; iii) three-dimensional random access with the ability to perform fast volume sweeps at kilohertz rates; and iv) fluorescence lifetime imaging. We demonstrate the ability to record action potentials with high temporal resolution using intracellularly loaded potentiometric dye di-2-ANEPEQ. Our design proffers easy integration with electrophysiology and promises a more widespread adoption of functional two-photon imaging as a tool for the study of neuronal activity. The software and firmware we developed is available for download at http://neurospy.org/ under an open source license

Development of SARS-CoV-2 N-protein specific capture ELISA

Ta na dijagnoza ljudi sa sumnjom na infekciju SARS-CoV-2 je od suštinskog zna aja zasuzbijanje globalnog širenja COVID-19. Prisustvo SARS-CoV-2 može se otkriti RT-PCRom (otkriva RNK virusa) ili detekcijom prisustva virusnih antigena u biološkim te nostimaELISA-om ili sli nom tehnikom koje koriste antitela razvijena u životinjama. Cilj studijeje bio uspostavljanje kvantitativnog testa koji se zasniva na koriš enju poliklonskih serumaza rutinsko odre ivanje koncentracije SARS-CoV-2 nukleokapsidnog proteina merenjamapsorbancije u standardnoj mikrotitarskoj plo ici sa 96 bunara. Za potrebe razvoja testaproizveden je rekombinantni N-protein i koriš en za proizvodnju antiseruma u miševima ize evima. Proizvedeni antiserumi su pre iš eni i odre en im je titar. Poliklonskiantiserumivisokog afiniteta specifi ni za N-protein koriš eni su za razvoj ELISA testa specifi nog zaovaj protein. Test se zasniva na koriš enju poliklonskih seruma miševa koji su adheriranina dno bunara mikrotitarske plo ice za hvatanje N-proteina iz uzorka. Razli itekoncentracije rekombinantnog N-proteina su koriš ene za standardnu krivu zakvantifikaciju proteina. N-protein vezan za antitela miševa je detektovan ze jimpoliklonskim serumom i anti-ze jim antitelom povezanim sa enzimom koji obezbe ujespektrofotometrijsko merenje. Uspešno smo razvili prototip ELISA testa za kvantifikacijuN-proteina sa granicom detekcije u opsegu od ng/mL. Prose na vrednost LOD za prototipELISA testa za detekciju N-proteina je 9,2 ng/mL, dok je prose na vrednost LOQ10,2 ng/mL. Pokazali smo da su proizvedeni poliklonski antiserumi pogodni za detekcijuN-proteina sa sli nim ili boljim afinitetom i specifi noš u od komercijalnih antitela.Štaviše, prototip ELISA testa se može koristiti sa zadovoljavaju om pouzdanoš u zakvantifikaciju N-proteina u uzorcima bogatim proteinima, poput ljudskih seruma.The accurate diagnosis of people with suspected infection with the SARS-CoV-2 isessential to curb the global spread of COVID-19. The presence of SARS-CoV-2 can bedetected by RT-PCR (it detects RNA of the virus) or by the presence of viral antigens inbiological fluids in ELISA or similar techniques using antibodies developed in animals.The aim of the study was the establishment of a quantitative polyclonal sera-based test forroutine measurement of the concentration of SARS CoV-2 nucleocapsid protein usingabsorbance measurement in a standard 96-well microtiter plate. For the purposes of the testdevelopment, recombinant N protein was produced and used for the production of miceand rabbit antisera. Produced antisera were purified and titer was determined. High-affinitypolyclonal N-protein specific antisera were used for N-protein specific ELISA testdevelopment. The test is based on mice polyclonal sera adhered to microtiter plate bottomfor the capture of the N protein from the specimen. Various concentrations of therecombinant N-protein were used to generate a standard curve for protein quantification.The N-protein bound to the mice antibodies was detected with rabbit polyclonal sera andanti-rabbit antibody coupled to an enzyme that provides spectrophotometric measurement.We have successfully developed the prototype ELISA for the quantification of N-proteinwith the detection limit being in the range of ng/mL. The average LOD value for theprototype ELISA was determined to be 9.2 ng/mL, while the average LOQ value was10.2 ng/mL. We have demonstrated that produced polyclonal antisera are suitable for thedetection of N-protein with affinity and specificity similar to, or better than commercialantibodies. Furthermore, the prototype ELISA can be used with satisfactory confidence forquantification of the N-protein in protein-rich samples, similar to human sera.Abstract: [https://cherry.chem.bg.ac.rs/handle/123456789/5361

Development of SARS-CoV-2 N-protein specific capture ELISA

Ta na dijagnoza ljudi sa sumnjom na infekciju SARS-CoV-2 je od suštinskog zna aja za suzbijanje globalnog širenja COVID-19. Prisustvo SARS-CoV-2 može se otkriti RT-PCRom (otkriva RNK virusa) ili detekcijom prisustva virusnih antigena u biološkim te nostima ELISA-om ili sli nom tehnikom koje koriste antitela razvijena u životinjama. Cilj studije je bio uspostavljanje kvantitativnog testa koji se zasniva na koriš enju poliklonskih seruma za rutinsko odre ivanje koncentracije SARS-CoV-2 nukleokapsidnog proteina merenjam apsorbancije u standardnoj mikrotitarskoj plo ici sa 96 bunara. Za potrebe razvoja testa proizveden je rekombinantni N-protein i koriš en za proizvodnju antiseruma u miševima i ze evima. Proizvedeni antiserumi su pre iš eni i odre en im je titar. Poliklonskiantiserumi visokog afiniteta specifi ni za N-protein koriš eni su za razvoj ELISA testa specifi nog za ovaj protein. Test se zasniva na koriš enju poliklonskih seruma miševa koji su adherirani na dno bunara mikrotitarske plo ice za hvatanje N-proteina iz uzorka. Razli ite koncentracije rekombinantnog N-proteina su koriš ene za standardnu krivu za kvantifikaciju proteina. N-protein vezan za antitela miševa je detektovan ze jim poliklonskim serumom i anti-ze jim antitelom povezanim sa enzimom koji obezbe uje spektrofotometrijsko merenje. Uspešno smo razvili prototip ELISA testa za kvantifikaciju N-proteina sa granicom detekcije u opsegu od ng/mL. Prose na vrednost LOD za prototip ELISA testa za detekciju N-proteina je 9,2 ng/mL, dok je prose na vrednost LOQ 10,2 ng/mL. Pokazali smo da su proizvedeni poliklonski antiserumi pogodni za detekciju N-proteina sa sli nim ili boljim afinitetom i specifi noš u od komercijalnih antitela. Štaviše, prototip ELISA testa se može koristiti sa zadovoljavaju om pouzdanoš u za kvantifikaciju N-proteina u uzorcima bogatim proteinima, poput ljudskih seruma.The accurate diagnosis of people with suspected infection with the SARS-CoV-2 is essential to curb the global spread of COVID-19. The presence of SARS-CoV-2 can be detected by RT-PCR (it detects RNA of the virus) or by the presence of viral antigens in biological fluids in ELISA or similar techniques using antibodies developed in animals. The aim of the study was the establishment of a quantitative polyclonal sera-based test for routine measurement of the concentration of SARS CoV-2 nucleocapsid protein using absorbance measurement in a standard 96-well microtiter plate. For the purposes of the test development, recombinant N protein was produced and used for the production of mice and rabbit antisera. Produced antisera were purified and titer was determined. High-affinity polyclonal N-protein specific antisera were used for N-protein specific ELISA test development. The test is based on mice polyclonal sera adhered to microtiter plate bottom for the capture of the N protein from the specimen. Various concentrations of the recombinant N-protein were used to generate a standard curve for protein quantification. The N-protein bound to the mice antibodies was detected with rabbit polyclonal sera and anti-rabbit antibody coupled to an enzyme that provides spectrophotometric measurement. We have successfully developed the prototype ELISA for the quantification of N-protein with the detection limit being in the range of ng/mL. The average LOD value for the prototype ELISA was determined to be 9.2 ng/mL, while the average LOQ value was 10.2 ng/mL. We have demonstrated that produced polyclonal antisera are suitable for the detection of N-protein with affinity and specificity similar to, or better than commercial antibodies. Furthermore, the prototype ELISA can be used with satisfactory confidence for quantification of the N-protein in protein-rich samples, similar to human sera.Poster: [https://cherry.chem.bg.ac.rs/handle/123456789/5362

Electrokinetic properties of hydroxyapatite under flotation conditions

The effect of calcite supernatant, calcium, and carbonate ions on the hydroxyapatite (HA) zeta potential without and in the presence of sodium oleate (1 x 10(-4) mol L-1) was examined within the pH range from 4 to 12. The interpretation of results was based on the HA Surface and oleate solution chemistry, and on some floatability tests. HA, with different positive and negative Surface sites formed depending on its solubility and pH, had a negative zeta potential over the whole pH range. This mineral is not naturally floatable (flotation recovery, 5% LT R LT 18%). The oleate ions (OI-), present in a very low concentration in an acidic medium (pH from 4.8 to 6), chemisorb individually on HA surface centers Ca+, HPO4Ca+, and OH2+, increasing the negative zeta potential of the mineral. Within the pH range from 7 to 9, the dominant oleate species OI- ion and ion-molecule complex, H(OI)(2)(+), adsorbed on HA by head groups toward the solid and associated due to chain-chain interaction in hemimicelles, made the HA surf ace with zeta potential about -22/-23 mV, and more floatable (R = 80-100%) than in 4 LT pH LT 7 (R = 15-35%) or in pH > 9.3. The HA surface is less negatively charged in calcite supernatant than in water from pH 6.6 to 9.2 due to the adsorption on HA negative surface active centers ( HPO4- and PO42+) of the Ca2+, CaHCO3+, and CaOH+ ions (present in the calcite supernatant), producing m re surface sites PO4Ca, HPO4CaOH, and PO4- CaOH, and new centers HPO4CaHCO3 and PO4- CaHCO3. In the presence of 1 x 10(-3) mol L-1 CaCl2, the HA sample has positive zeta potential, the same as calcite from the same deposit, up to IEP at pH 11.25. Carbonate ions (1 x 10(-3) mol L-1 Na2CO3) do not affect the HA zeta potential. However, a possible process can be the ion-exchange reaction between bicarbonate (or carbonate) and some anion from the surface sites formed on HA. The obtained values of the HA zeta potential with the collector (1 x 10(-4) mol L-1 Na-oleate) added into hydroxyapatite/calcite Supernatant suspensions corroborate the weak chemisorption of OI- and H(OI)(2)(-). The likely processes in this system also are the ion-exchange reactions on HPO4CaOH and PO4- CaOH, HPO4CaHCO3 and PO4- CaHCO3 between oleate ion and surface hydroxyl and bicarbonate ions, Surface and bulk precipitations of calcium oleate. Ca(OI)(2), and the Surface and bulk precipitations of Ca[H(OI)(2)(-)](2) over the pH range from 7 to 9. Calcite Supernatant does not influence natural floatability of the mineral. However, calcite Supernatant depresses the hydroxyapatite flotation in the presence of 1 x 10(-4) mol L-1 Na-oleate (pH 9, R similar to 50%), a likely result of the weak chemisorption due to the steric effect of heterogeneous HA surface formed in calcite supernatant, Ca(OI)(2) and Ca[H(OI)(2)(-)](2) surface and bulk precipitations