104 research outputs found
Supplementary data for article : Panic, V. V.; Seslija, S. I.; Popovic, I. G.; Spasojevic, V. D.; Popovic, A. R.; Nikolic, V. B.; Spasojevic, P. M. Simple One-Pot Synthesis of Fully Biobased Unsaturated Polyester Resins Based on Itaconic Acid. Biomacromolecules 2017, 18 (12), 3881–3891. https://doi.org/10.1021/acs.biomac.7b00840
Supporting information for: [https://doi.org/10.1021/acs.biomac.7b00840]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2568]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3058
The application of physicochemical methods for the analysis of radiation processed food products
The aim of this study was to investigate the occurrence and stability of free radicals in freeze-dried samples of cow milk, pineapple and banana after irradiation (10 kGy dose), using the ESR spectroscopy, as well as to assess possible changes in their protein structure by means of electrophoresis.The Conference is dedicated to the 100th Anniversary of the academician Pavle Savić birthday and 20th Anniversary of the Society of Physical Chemists of SerbiaPhysical chemistry 2010 : 10th international conference on fundamental and applied aspects of physical chemistry; September 21-24, Belgrade, 2012
The Effect of Glycol Derivatives on the Properties of Bio-Based Unsaturated Polyesters
The scope of the present study was to prepare fully bio-based unsaturated polyester resins (UPRs) with comparable properties to the commercial formulations. The focus was set on the determination of the optimal prepolymer formulation using the same set of diacids (itaconic and succinic acid) and different diols (propylene glycol, isosorbide and neopentyl glycol) or its equimolar mixtures, keeping the fixed molar ratio of 1:1:2.1 in all feed compositions. Instead of commonly used styrene, bio-based dimethyl itaconate was used as a reactive diluent (RD). The rheology of the obtained resins was studied in detail. The effect of the used diol on structural (FTIR), thermal (DSC), thermomechanical (DMA), and mechanical (tensile) properties was explained. The properties of UPRs were found to be highly dependent on the diol used in the prepolymer formulation. The UPR with an equimolar ratio of propylene glycol and neopentyl glycol was shown to be the most promising candidate to compete with the commercial petroleum-based resins
Supplementary data for article : Panic, V. V.; Seslija, S. I.; Popovic, I. G.; Spasojevic, V. D.; Popovic, A. R.; Nikolic, V. B.; Spasojevic, P. M. Simple One-Pot Synthesis of Fully Biobased Unsaturated Polyester Resins Based on Itaconic Acid. Biomacromolecules 2017, 18 (12), 3881–3891. https://doi.org/10.1021/acs.biomac.7b00840
Supporting information for: [https://doi.org/10.1021/acs.biomac.7b00840]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2568]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3058
Biohidrogelovi poli(metakrilne kiseline): bubrenje i kontrolisano otpuštanje kofeina
Modern society are faced with lot of challenges in the treatment of many diseases, especiallywith serious ones such as cancer. Safer and more efficient treatment of the cancer patients are maingoals which researchers are aiming. One of the good approaches can be drug delivery systems.Still, a lot of anticancer drugs are poorly water-soluble and their encapsulation and controlled releasecan be quite challenging. Present study is focused to improve drug delivery system based onhydrophilic poly(methacrylic acid) and amphiphilic casein with encapsulated poorly water-solublecaffeine, which has been developed through our previous research. The hydrogels with 1.6mol% ofcrosslinker and 100% of neutralization degree of methacrylic acid are synthetized (PMAC-100N-4M). The swelling process of the PMAC-100N-4M hydrogels and caffeine release are analyzed intwo environments which simulate human stomach and intestines. It is also investigated how thechange in the encapsulated caffeine weight and the addition of liposomes with encapsulated caffeine,affect swelling degree of the PMAC-100N-4M hydrogels and release of caffeine. The resultsshow that controlled release of caffeine is improved, therefore overall therapy can be enhanced.Savremeno društvo je suočeno sa mnogim izazovima u tretamanu raznih bolesti, naročito ozbiljnih oboljenja kao što je rak. Glavni ciljevi naučnika su da se postigne bezbednija i efikasnija terapija pacijenata koji se leče od raka. Jedan od dobrih načina da se to postigne su sistemi za dostavu lekova. Ipak, mnogi antikancerogeni lekovi su slabovodorastvorni, pa bi veliki izazov mogao da bude inakpsulacija i njihovo kontorlisano otpuštanje iz sistema za dostavu lekova. Cilj ovog rada je da se unapredi sistem za dostavu lekova na bazi hidrofilne poli(metakrilne kiseline) i amfifilnog kazeina sa inkapsuliarnim slabo vodorastvornim kofeinom, koji je razvijen tokom našeg prethodnog istraživanja. U ovom radu sintetisani su hidrogelovi sa 1,6mol% umreživača i 100% neutralisanom metakrilnom kiselinom (PMAC-100N-4M). Procesi bubrenja PMAC-100N-4M hidrogelova i kontrolisanog otpuštanja kofeina su ispitivani u dve sredine koje simuliraju želudac i tanko crevo čoveka. Takođe je ispitano kako promena količine inkapsuliranog kofeina i dodatak lipozomne suspenzije sa inkapsuliranim kofeinom utiče na procese bubrenja PMAC-100N-4M hidorgelova i otpuštanje kofeina. Rezultati pokazuju da je proces kontrolisanog otpuštanje kofeina unapređen, a samim tim je moguće unaprediti i celokupnu terapiju
Ultrazvučna ekstrakcija pektina iz otpadne jabučne kaše primenom eutektičkih rastvarača na bazi holin hlorida
Pectin and pectin derived oligosaccharides can be obtained from waste apple pomace(biomass). Traditional method for pectin extraction involves use of diluted mineral acids atelevated temperatures, with yields of about 10 to 15%. As an alternative to conventionalmethods, the use of eutectic solvents is increasing because of their superior propertieswhen it comes to targeted extraction of certain components from biomass. The aim of thispaper is ultrasound assisted extraction of pectin from waste apple pomace using cholinechloride based eutectic solvents and lactic acid. Properties of extracted products wereexamined using FTIR spectroscopy and differential scanning calorimetry.Pektin i pektinski oligosaharidi mogu se dobiti iz otpadne jabučne kaše. Ovaj prirodni polimer ima široku primenu u industriji. Tradicionalna metoda za ekstrakciju pektina podrazumeva tretman razblaženim mineralnim kiselinama na povišenoj temperaturi, pri čemu se prinosi ostvaruju od oko 10 do 15%. Kao alternativa tradicionalnim rastvaračima sve češće se koriste i eutektički rastvarači, koje odlikuju daleko superiornija svojstva kada je reč o ciljanoj ekstrakciji određenih komponenti iz biomase. Cilj ovog rada je ultrazvučna ekstrakcija pektina primenom eutektičkih rastvarača na bazi holin hlorida i mlečne kiseline. Svojstva ekstrahovanog proizvoda ispitana su primenom FTIR spektroskopije i diferencijalne skenirajuće kalorimetrije
Bench-to-bedside review : targeting antioxidants to mitochondria in sepsis
Peer reviewedPublisher PD
Physicochemical characteristics of gamma irradiation crosslinked poly(vinyl alcohol)/magnetite ferrogel composite
Magnetic field sensitive gels, ferrogels, are new promising class of hydrogels. The coupling of hydrogels and magnetic particles has potential application in soft actuators, such as artificial muscles, or for hyperthermia application. In this study, the composite of magnetite particles (Fe3O4) and poly(vinyl alcohol) (PVA) hydrogel is developed using gamma irradiation as a crosslinking agent. PVA and Fe3O4 were chosen due to their well-established biocompatibility, radiation crosslinking potential (PVA), mild magnetic properties and the Curie point near desired heating temperature range (Fe3O4). Physicochemical characteristics of these systems show the effect of the presence of particles in the process of radiation-induced crosslinking. Obtained PVA/Fe3O4 ferrogel composite has greater swelling capacity, activation energy of dehydration and dehydration rate compared to PVA hydrogel, crosslinked under the same conditions
Demagnetization via Nucleation of the Nonequilibrium Metastable Phase in a Model of Disorder
We study both analytically and numerically metastability and nucleation in a
two-dimensional nonequilibrium Ising ferromagnet. Canonical equilibrium is
dynamically impeded by a weak random perturbation which models homogeneous
disorder of undetermined source. We present a simple theoretical description,
in perfect agreement with Monte Carlo simulations, assuming that the decay of
the nonequilibrium metastable state is due, as in equilibrium, to the
competition between the surface and the bulk. This suggests one to accept a
nonequilibrium "free-energy" at a mesoscopic/cluster level, and it ensues a
nonequilibrium "surface tension" with some peculiar low-T behavior. We
illustrate the occurrence of intriguing nonequilibrium phenomena, including:
(i) Noise-enhanced stabilization of nonequilibrium metastable states; (ii)
reentrance of the limit of metastability under strong nonequilibrium
conditions; and (iii) resonant propagation of domain walls. The cooperative
behavior of our system may also be understood in terms of a Langevin equation
with additive and multiplicative noises. We also studied metastability in the
case of open boundaries as it may correspond to a magnetic nanoparticle. We
then observe burst-like relaxation at low T, triggered by the additional
surface randomness, with scale-free avalanches which closely resemble the type
of relaxation reported for many complex systems. We show that this results from
the superposition of many demagnetization events, each with a well- defined
scale which is determined by the curvature of the domain wall at which it
originates. This is an example of (apparent) scale invariance in a
nonequilibrium setting which is not to be associated with any familiar kind of
criticality.Comment: 26 pages, 22 figure
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