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

Dual responsive hybrid hydrogels for controlled release of local anesthetic

Inteligentni hidrogelovi, kao što su pH osetljivi hidrogelovi na bazi poli(metakrilne kiseline) (PMAA), imaju veliku primenu u ciljanoj dostavi lekova. Međutim, slaba mehanička svojstva često ograničavaju primenu PMAA. Kako bi se prevazišlo navedeno ograničenje, nanoceluloza (NC) je prvo ekstrakovana iz drvnog otpadnog materijala, a zatim dodata u PMAA, zato što je NC biokompatibilna, netoksična i ima odlična mehanička svojstva. Zatim je dodata karboskimetil celuloza (CMC) (celulozni derivat koji se često koristi za kontrolisano otpuštanje lekova). CMC može da stabilizuje nanočestice magnetita (MN) koje su takođe dodate. MN mogu značajno da poboljšaju mehanička svojstva hidrogelova i takođe poseduju magnetna svojstva zbog čega imaju primenu za ciljano otpuštanje lekova. Ovako dobijeni materijal bi mogao da zaštiti lek, dostavi ga do mesta delovanja, kontroliše brzinu njegovog otpuštanja i na taj način omogući efikasno dejstvo leka sa smanjenim neželjenim efektima. Lokalni anestetik – lidokain hidrohlorid (LH) se često u tretmanima injektira što može imati ozbiljne neželjene efekte. Inkapsulacijom LH u hidrogelove na bazi PMAA, NC, CMC i MN (PMNC/MN-L) rešen je navedeni problem. Karakterizacija PMNC/MN-L hidrogelova je izvedena primenom FTIR i SEM spektroskopija i kompresionim testovima, a zatim je analizirano bubrenje hidrogelova i otpuštanje LH. U ovom radu predstavljen je jedinstveni način „zelene” sinteze hibridnih hidrogelova osetljivih na spoljne stimulanse unapređenih svojstava i njihove primene za kontrolisano otpuštanje lokalnog anestetika sa smanjenim neželjnim efektima

Effects of chronic diazepam treatments on behavior on individually housed rats

The present study analyzed the effects of chronic treatment with low doses of diazepam on body weight, defecations and urinations, vertical rears, the elevated platform test; and self-grooming in male rats exposed for 21 days to social isolation. The rats were treated for 21 days with diazepam (0.2 mg/kg, i.p) or its vehicle. Social isolation led to decreased body weight and vertical rears, more defecations and urinations, increased reluctance to step down from the test platform, shorter duration of grooming, and longer reluctance to start grooming. Chronic diazepam in individually housed rats produced increase in body weight and vertical rears, decrease in the number of defecations and urinations, and shortening of the time of reluctance to step down from the platform. The number of grooming bouts, their duration, and reluctance to start grooming were not altered by diazepam, but it decreased the percentage of incorrect transitions. The obtained data indicate that chronic diazepam treatment of socially isolated rats changes non-grooming behavior and some grooming, behavior parameters

Characterization of glycidyl methacrylate based magnetic nanocomposites

Magnetic and non-magnetic macroporous crosslinked copolymers of glycidyl methacrylate and trimethylolpropane trimethacrylate were prepared by suspension copolymerization and functionalized with diethylenetriamine. The samples were characterized by mercury porosimetry, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy analysis (FTIR-ATR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM) and SQUID magnetometry. The FTIR-ATR analysis of synthesized magnetic nanocomposites confirmed the presence of magnetite and successful aminofunctionalization. Non-functionalized and amino-functionalized nanocomposites exhibited superparamagnetic behavior at 300 K, with a saturation magnetization of 5.0 emu/g and 2.9 emu/g, respectively. TEM analysis of the magnetic nanocomposite has shown that magnetic nanoparticles were homogeneously dispersed in the polymer matrix. It was demonstrated that incorporation of magnetic nanoparticles enhanced the thermal stability of the magnetic nanocomposite in comparison to the initial non-magnetic macroporous copolymer

Nonuniversal scaling behavior of Barkhausen noise

We simulate Barkhausen avalanches on fractal clusters in a two-dimensional diluted Ising ferromagnet with an effective Gaussian random field. We vary the concentration of defect sites $c$ and find a scaling region for moderate disorder, where the distribution of avalanche sizes has the form $D(s,c,L) = s^{-(1+\tau (c))}{\cal{D}}(sL^{-D_s(c)})$. The exponents $\tau (c)$ for size and $\alpha (c)$ for length distribution, and the fractal dimension of avalanches $D_s(c)$ satisfy the scaling relation $D_s(c)\tau (c) =\alpha (c)$. For fixed disorder the exponents vary with driving rate in agreement with experiments on amorphous Si-Fe alloys.Comment: 5 pages, Latex, 4 PostScript figures include

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

Characterization of poly(N-izopropylacrylamide) hydrogel nanocomposites influenced by anizotropic silver nanoparticles

Hydrogels possess distinctive characteristics that can be tailored to meet specific needs, especially in the field of biosciences, which is continuously expanding and advancing. Adjustability of gel porosity, followed by tunability of swelling properties, environmental responsiveness, and stability, are properties that are easily adjusted, offering researchers and engineers the flexibility to fine-tune these properties to suit the specific requirements of diverse applications. As a result of environmental responsivity, one class of these materials emerged, referred to as stimuli-responsive or smart hydrogels. Such hydrogels can change their properties in response to specific external stimuli or environmental conditions in a controlled and reversible manner. Depending on the specific type of smart hydrogel, this feature can enable targeted drug delivery, tissue engineering, and controlled release systems while maintaining their biocompatibility. Poly(N-isopropylacrylamide) (PNiPAAm) is a thermosensitive polymer with a well-defined volume phase transition temperature (VPTT) around 32°C. Conversely, silver nanoparticles (AgNPs) continue to preserve academic interest due to their size-dependent optical, catalytic, and electronic properties, as well as their significant antimicrobial potential. One of the primary obstacles encountered by scientists is establishing the broader range of practical applications of AgNPs as well as improving the existing ones. Optimizing their properties often involves controlling size and shape, stability, and surface properties. In order to determine how anizotropic Ag NPs alter and influence the physicochemical properties of PNiPAAm we present a simple, straightforward two-step synthesis of AgNPs/PNiPAAm hydrogel nanocomposites. This method involves the chemical synthesis of both spherical and triangular AgNPs, followed by the crosslinking of PNiPAAm through gamma irradiation in the presence of nanoparticles. The validation of employing gamma irradiation is based on the fact that this technology integrates the processes of sterilization and synthesis, resulting in a consolidated technical step that enhances efficiency and enables the exploration of numerous innovative biomedical applications. The porous sponge-like structure was observed by SEM analysis, while the formation of stable and uniformly distributed AgNPs in the polymer was confirmed by UV-VIS spectroscopy. Swelling and deswelling processes were performed in water at 25C and 48C, respectively. In addition, AgNPs were shown to influence VPTT values. The primary objective of this study is to examine the correlation between various morphologies of AgNPs and the physicochemical characteristics of nanocomposite samples. This investigation considers the possible uses and the current demand for the extensive utilization of biocompatible materials.29th International Symposium on Analytical and Environmental Problems (November 13-14, 2023; Szeged, Hungary

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

Investigation of EMIC wave scattering as the cause for the BARREL 17 January 2013 relativistic electron precipitation event: A quantitative comparison of simulation with observations

Abstract Electromagnetic ion cyclotron (EMIC) waves were observed at multiple observatory locations for several hours on 17 January 2013. During the wave activity period, a duskside relativistic electron precipitation (REP) event was observed by one of the Balloon Array for Radiation belt Relativistic Electron Losses (BARREL) balloons and was magnetically mapped close to Geostationary Operational Environmental Satellite (GOES) 13. We simulate the relativistic electron pitch angle diffusion caused by gyroresonant interactions with EMIC waves using wave and particle data measured by multiple instruments on board GOES 13 and the Van Allen Probes. We show that the count rate, the energy distribution, and the time variation of the simulated precipitation all agree very well with the balloon observations, suggesting that EMIC wave scattering was likely the cause for the precipitation event. The event reported here is the first balloon REP event with closely conjugate EMIC wave observations, and our study employs the most detailed quantitative analysis on the link of EMIC waves with observed REP to date. Key PointsQuantitative analysis of the first balloon REP with closely conjugate EMIC wavesOur simulation suggests EMIC waves to be a viable cause for the REP eventThe adopted model is proved to be applicable to simulating the REP event

How self-organized criticality works: A unified mean-field picture

We present a unified mean-field theory, based on the single site approximation to the master-equation, for stochastic self-organized critical models. In particular, we analyze in detail the properties of sandpile and forest-fire (FF) models. In analogy with other non-equilibrium critical phenomena, we identify the order parameter with the density of ``active'' sites and the control parameters with the driving rates. Depending on the values of the control parameters, the system is shown to reach a subcritical (absorbing) or super-critical (active) stationary state. Criticality is analyzed in terms of the singularities of the zero-field susceptibility. In the limit of vanishing control parameters, the stationary state displays scaling characteristic of self-organized criticality (SOC). We show that this limit corresponds to the breakdown of space-time locality in the dynamical rules of the models. We define a complete set of critical exponents, describing the scaling of order parameter, response functions, susceptibility and correlation length in the subcritical and supercritical states. In the subcritical state, the response of the system to small perturbations takes place in avalanches. We analyze their scaling behavior in relation with branching processes. In sandpile models because of conservation laws, a critical exponents subset displays mean-field values ($\nu=1/2$ and $\gamma = 1$) in any dimensions. We treat bulk and boundary dissipation and introduce a new critical exponent relating dissipation and finite size effects. We present numerical simulations that confirm our results. In the case of the forest-fire model, our approach can distinguish between different regimes (SOC-FF and deterministic FF) studied in the literature and determine the full spectrum of critical exponents.Comment: 21 RevTex pages, 3 figures, submitted to Phys. Rev.