Kinetics and column adsorption study of diclofenac and heavy-metal ions removal by amino-functionalized lignin microspheres

Ana L. Popovic,Jelena D. Rusmirovic,Zlate Velickovic,Tihomir Kovacevic,Aleksandar Jovanovic,Ilija Cvijetic,Aleksandar D. Marinkovic 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.93 No.-

In-depth kinetic and column adsorption study for diclofenac, DCF, heavy-metal and oxyanions adsorptionon highly effective amino-functionalized lignin-based microsphere adsorbent (A-LMS) is examined. TheA-LMS was synthesized via inverse suspension copolymerization of industrial kraft lignin with the aminocontaining grafting-agent (polyethylene imine), and an epoxy chloropropane cross-linker. The batchadsorption results indicated process spontaneity and feasibility of a high removal capacity: DCF(151.13)>>Cd2+(74.84)>Cr(VI)(54.20)>As(V)(53.12)>Ni2+(49.42 mg g 1). The quantum chemical calculatedinteraction energies reveal stabilization of the A-LMS/DCF complex through the electrostatics and vander Waals interactions. The results from the pseudo-second order and Weber-Morrisfitting indicate a fastremoval rate; thus, column tests were undertaken. The single resistance mass transfer model, i.e. themass transfer (kfa) and diffusion coefficient (Deff), shows pore diffusional transport as a rate limiting step. Thefitting of thefixed bed column data with empirical models demonstrates the influences offlow rateand adsorbate inlet concentration on the breakthrough behavior. Pore surface diffusion modeling (PSDM)expresses mass transport under applied hydraulic loading rates, calculated breakthrough pointadsorption capacities: Cd2+(58.1)>Cr(VI)(54.1)>As(V)(50.9)>>Ni2+(42.9 mg g 1)), without performingthe experimentation on a full pilot-scale level, further confirms the high applicability of the A-LMS biobasedadsorbent.

Optimal Utilization of Low Voltage GaN HEMT in High Frequency Boost Converter

Wenbo Wang,Frans Pansier,Jelena Popovic,J.A. Ferreira 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In this paper, investigations on optimal topology and operation mode for low voltage GaN HEMT are performed. Analytical loss model of GaN HEMT, in which influences of circuit and package parasitics are accounted for, is developed as a tool to analyze losses in GaN HEMT in different switching conditions. Analysis results shows that when applied in both Vout〈2Vin and Vout〉2Vin situations in Boundary Conduction Mode with Valley Switching(BCM-VS) in a boost converter, where GaN HEMT is switched on when voltage across it is lowered, switching loss can be greatly reduced. Switching loss reduction results not only from the exemption of discharging the large output capacitance of GaN HEMT at high voltage, but also from the fact that parasitic inductance has much less effects on switching loss in GaN HEMT in BCM-VS than in Continuous Conduction Mode (CCM). Limitations and design tradeoffs when GaN HEMT is applied in BCM-VS are also revealed. Forward voltage of GaN HEMT in reverse conduction is high and its conduction should be prevented when Vout〉 to achieve conduction loss reduction. This further loss reduction can be realized by switching on transistor before valley point. Besides, in BCM-VS, overvoltage on GaN HEMT is larger and oscillatory energy dissipation in circuit is higher than in CCM due to higher turn off current. Paralleling external capacitor to the transistor helps to ease voltage stress; however turn on loss will be increased. This loss increase is more severe in the case of Vout〈2Vin than Vout〉2Vin. Trade-offs on the selection of proper external capacitor value exists between increased switching loss and reduced voltage stress. Experimental setup is built to verify and demonstrate the analysis.

Correlations among Stress Parameters, Meat and Carcass Quality Parameters in Pigs

Dokmanovic, Marija,Baltic, Milan Z.,Duric, Jelena,Ivanovic, Jelena,Popovic, Ljuba,Todorovic, Milica,Markovic, Radmila,Pantic, Srdan Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.3

Relationships among different stress parameters (lairage time and blood level of lactate and cortisol), meat quality parameters (initial and ultimate pH value, temperature, drip loss, sensory and instrumental colour, marbling) and carcass quality parameters (degree of rigor mortis and skin damages, hot carcass weight, carcass fat thickness, meatiness) were determined in pigs (n = 100) using Pearson correlations. After longer lairage, blood lactate (p<0.05) and degree of injuries (p<0.001) increased, meat became darker (p<0.001), while drip loss decreased (p<0.05). Higher lactate was associated with lower initial pH value (p<0.01), higher temperature (p<0.001) and skin blemishes score (p<0.05) and more developed rigor mortis (p<0.05), suggesting that lactate could be a predictor of both meat quality and the level of preslaughter stress. Cortisol affected carcass quality, so higher levels of cortisol were associated with increased hot carcass weight, carcass fat thickness on the back and at the sacrum and marbling, but also with decreased meatiness. The most important meat quality parameters (pH and temperature after 60 minutes) deteriorated when blood lactate concentration was above 12 mmol/L.

Correlations among Stress Parameters, Meat and Carcass Quality Parameters in Pigs

Marija Dakmanovic,Milan Z. Baltic,Jelena Duric,Jelena Ivanovic,Ljuba Popovic,Milica Todorovic,Radmila Markovic,Srdan Pantic 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.3

Relationships among different stress parameters (lairage time and blood level of lactate and cortisol), meat quality parameters (initial and ultimate pH value, temperature, drip loss, sensory and instrumental colour, marbling) and carcass quality parameters (degree of rigor mortis and skin damages, hot carcass weight, carcass fat thickness, meatiness) were determined in pigs (n = 100) using Pearson correlations. After longer lairage, blood lactate (p<0.05) and degree of injuries (p<0.001) increased, meat became darker (p<0.001), while drip loss decreased (p<0.05). Higher lactate was associated with lower initial pH value (p<0.01), higher temperature (p<0.001) and skin blemishes score (p<0.05) and more developed rigor mortis (p<0.05), suggesting that lactate could be a predictor of both meat quality and the level of preslaughter stress. Cortisol affected carcass quality, so higher levels of cortisol were associated with increased hot carcass weight, carcass fat thickness on the back and at the sacrum and marbling, but also with decreased meatiness. The most important meat quality parameters (pH and temperature after 60 minutes) deteriorated when blood lactate concentration was above 12 mmol/L.

BMB Reports : Cyclic AMP response element binding (CREB) protein acts as a positive regulator of SOX3 gene expression in NT2/D1 cells

( Natasa Kovacevic Grujicic ),( Marija Mojsin ),( Jelena Popovic ),( Isidora Petrovic ),( Vladanka Topalovic ),( Milena Stevanovic ) 생화학분자생물학회 2014 BMB Reports Vol.47 No.4

SOX3 is one of the earliest neural markers in vertebrates, playing the role in specifying neuronal fate. In this study we have established first functional link between CREB and human SOX3 gene which both have important roles in the nervous system throughout development and in the adulthood. Here we demonstrate both in vitro and in vivo that CREB binds to CRE half-site located -195 to -191 within the human SOX3 promoter. Overexpression studies with CREB or its dominant-negative inhibitor A-CREB indicate that this transcription factor acts as a positive regulator of basal SOX3 gene expression in NT2/D1 cells. This is further confirmed by mutational analysis where mutation of CREB binding site results in reduction of SOX3 promoter activity. Our results point at CREB as a positive regulator of SOX3 gene transcription in NT2/D1 cells, while its contribution to RA induction of SOX3 promoter is not prominent. [BMB Reports 2014; 47(4): 197-202]

Isoflavone Composition, Total Polyphenolic Content, and Antioxidant Activity in Soybeans of Different Origin

Vesna Tepavčević,Milica Atanackovic,Jegor Miladinovic,Djordje Malencˇic,Jovan Popovic,Jelena Cvejic 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.3

Twenty soybean cultivars, originating from the United States, Russia, Serbia, and China, were analyzed for their isoflavone composition, total polyphenolic content, and antioxidant activity. Isoflavones were extracted by aqueous methanol (80%) and analyzed by high-performance liquid chromatography/diode array detection. Precision and linearity of the applied method were within the standard limits of validation. The highest and the lowest total isoflavone contents were 4.59 and 1.45mg/g of dried soybean weight, respectively. A significant difference (P<.05) was found in isoflavone concentration among the different cultivars, but it was observed that origin is not a significant factor that could influence isoflavone content in soybeans. Total polyphenolic content varied between 2.13 and 3.45mg of gallic acid equivalents/g of dried soybean weight. The free radical scavenging activity of soybean extracts assayed by 2,2-diphenyl-1-picrylhydrazyl in terms of 50% inhibitory concentration (IC50) ranged from 1.40 to 3.35mg/mL. Negative correlation between total polyphenolic content and IC50 was observed, but there was no correlation between total isoflavone content and IC50. On the basis of this study, soybean cultivars with larger potency for biological activity could be recognized.