CYTOKINE PROFILE IN RENAL TRANSPLANT PATIENTS IN A LONG-TERM PERIOD AFTER SURGERY

In the long-term period after kidney transplantation, a certain level of tissue inflammation and therefore the production of proinflammatory cytokines, including TNF-α, IL-1β, IL-18 and IL-2 can be found. The aim of our study was to determine the concentrations of TNF-α, IL-1β, IL-18, IL-2 and its soluble receptor (IL-2R) in renal transplant patients, regarding the length of the postoperative period. The study involved 65 patients, transplanted at least 12 months prior to our investigation, divided into three groups, regarding the time passed since the transplantation (12-24, 24-48, and >48 months consecutively). Concentrations of the cytokines in the plasma of the subjects were measured using ELISA method. Group I showed significantly higher concentrations of IL-1b compared to the III (p<0.05), IL-18 compared to the II and III (p<0.05) and TNF-a compared to the II (p<0.05). Cytokine concentrations correlated with the time passed since the transplantation (p<0.05), except for TNF-a. Interleukin-2 correlated negatively with IL-18 and immunosuppressant dosage (p<0.05). Interleukin-1b, IL-18 and TNF-α measurements should be considered for monitoring and detecting potentially subclinical allograft damage in the second year after surgery. However, the dynamics of the change of cytokine concentration may also have been altered by the components of the immunosuppressive protocols used, such as tacrolimus, which is a link that is yet to be examined

Consideration of Energy Flows in the Life Cycle of Energy Production from Biogas

The aim of this paper is to present the energy flows in the life cycle of the biogas cogeneration system, as well as their mutual relations, starting from providing of feedstock materials(corn silage and cow manure), anaerobic digestion, cogeneration up to the digestate as fertilizer on agricultural land. The cogeneration process has been considered according to the performance of the biogas plant located on the Mirotin dairy farm in Vrbas (Serbia). For evaluation of energy flows in this work were used four energy indicators. According to the Life Cycle Energy Assessment approach, results obtained in this study have shown that the biogas cogeneration process has positive energy balances and this process is energy sustainable. The applied approach in this research can be adjusted to any biogas power plant since it complies with the main material and energy balances.Cilj ovog rada je da prikaže tokove energije u životnom ciklusu biogas kogeneracionog sistema, kao i njihove međusobne odnose, počev od obezbeđivanja sirovine (kukuruzna silaža i kravlji stajnjak), anaerobne digestije, kogeneracije, pa do digestata. kao đubrivo na poljoprivrednom zemljištu. Proces kogeneracije je razmatran prema performansama biogas postrojenja koje se nalazi na farmi mleka Mirotin u Vrbasu (Srbija). Za evaluaciju energetskih tokova u ovom radu korišćena su četiri energetska indikatora. Prema LCEA pristupu, rezultati dobijeni u ovoj studiji su pokazali da proces kogeneracije biogasa ima pozitivan energetski bilans i da je ovaj proces energetski održiv. Primenjeni pristup u ovom istraživanju može se prilagoditi bilo kojoj elektrani na biogas jer je u skladu sa osnovnim materijalnim i energetskim bilansima

Biogas tehnologija u funkciji proizvodnje energije

Potreba za smanjenjem upotrebe fosilnih goriva, zbog štetnog uticaja na životnu sredinu i sve veća potražnja za energijom, doveli su do proizvodnje energije iz obnovljivih izvora. Pristup čistoj i obnovljivoj energiji postao je imperativ za društveni napredak. Poboljšanje postojećih resursa biomase u efikasne nosioce energije kao što je biogas iz anaerobne digestije ima potencijal da obezbedi čistu i pouzdanu energiju, uz zaštitu životne sredine, racionalno korišćenje prirodnih resursa i stvaranje novih radnih mesta. Uz smanjenje emisije gasova staklene bašte, biogas poboljšava energetsku sigurnost i, kao obnovljivi izvor energije, omogućava eksploataciju otpadnih tokova. Biogas proizveden u sistemu anaerobne digestije se obično sagoreva u kogeneracionoj jedinici da bi se proizvela toplota, električna energija i energija za hlađenje. Konačno, biogas se može prečistiti u biometan, koristiti kao gorivo u vozilima ili ubrizgati u nacionalne mreže prirodnog gasa. Digestat kao nusproizvod anaerobne digestije je pouzdan materijal za upotrebu kao đubrivo u poljoprivredi. U ovom radu sumirano je korišćenje biogasa za proizvodnju toplotne, električne energije, rashladne energije, kao i goriva sa pregledom postojećih tehnologija za njegovu upotrebu. Takođe, ovaj rad pruža priliku da se razmotri uloga biogasa u budućim energetskim sistemima.The need to reduce the use of fossil fuels, due to the harmful impact on the environment and the growing energy demand, have led to the production of energy from renewable sources. Access to clean and renewable energy has become imperative for social progress. Improving existing biomass resources into efficient energy carriers such as biogas from anaerobic digestion has the potential to provide clean and reliable energy, with environmental protection, rationally using natural resources and generation of new jobs. Along with reducing greenhouse gas emissions, biogas improves energy security and, as a renewable energy source, enables the exploitation of waste streams. Biogas produced in an anaerobic digestion system is usually burned in a cogeneration unit to produce heat, electricity, and cooling energy. Finally, biogas can be purified into biomethane, used as a fuel for vehicles, or injected into national natural gas networks. Digestate as a by-product of anaerobic digestion is a reliable material for use as a fertilizer in agriculture. This paper summarizes the use of biogas for the production of heat, electricity, cooling energy, as well as fuel with an overview of existing technologies for its use. Also, this paper provides an opportunity to consider the role of biogas in future energy systems

Possibility of waste biomass of hops utilisation for adsorption of Ni2+ ions from aqueous solutions

Загађење водених екосистема изазвано никлом представља озбиљну еколошку претњу током последњих неколико деценија и од великог је еколошког значаја. Ова забринутост произилази из чињенице да је никл биоразградив, високотоксичан и да потенцијално може изазвати бројне штетне ефекте по здравље људи. У овом раду испитана је биосорпција јона никла при различитим контактним временима коришћењем отпадне биомасе хмеља. Висока вредност коефицијента корелације од 0,999 указује да кинетика адсорпције прати модел псеудо-другог реда. Хмељ је показао висок потенцијал у уклањању Ni2+ из водених раствора са ефикасношћу до 86%. Коришћење отпадне биомасе хмеља бити ефикасна, економична и еколошки погодна опција за очување животне средине.Nickel pollution of aquatic ecosystems has been a serious environmental threat during the last few decades and is of great environmental importance. This concern stems from the fact that nickel is biodegradable, highly toxic, and can potentially cause numerous adverse effects on human health. In this work, the biosorption of nickel ions at different contact times was investigated using hop biomass waste. The high correlation coefficient value of 0.999 indicates that the adsorption kinetics follows a pseudo-second-order model. Hops showed high potential for Ni2+ removal from aqueous solutions with an efficiency ofup to 86%. The use of waste biomass of hops can be an efficient, economical and ecologically suitable option for the preservation of the environment

Extraction of novel exopolysaccharide as potential biosorbent for removal of Ni2+ ions from contaminated water

Lactic acid bacteria synthesize metabolites that can be used in pharmaceutical, food, water, and dairy industries. Hence, in this study, a novel exopolysaccharide was extracted and isolated from the probiotic strain L. reuteri B2, assessed on possible application as a biosorbent for removal of heavy metals from the contaminated water. Novel exopolysaccharide was characterized using SEM, and TGA/DTG analysis. Our hypothesis was that if this EPS can be used as potentinal biomaterial, than its application for nickel removal from the contaminated water can be performed. After biosorption experiments, the removal efficiency of Ni2+ from the aqueous solution was 92.96%. According to these results, this exopolysaccharide can be considered as a very promising biomaterial for application in different industries, from pharmacy to treatments of contaminted waterBakterije mlečne kiseline sintetišu metabolite koji se mogu koristiti u farmaceutskoj, prehrambenoj, vodenoj i mlečnoj industriji. S toga, u ovoj studiji je ekstrahovan i izolovan novi egzopolisaharid iz probiotičkog soja L. reuteri B2, koji je testiran za moguću primenu kao biosorbent za uklanjanje teških metala iz kontaminirane vode. Novi egzopolisaharid je okarakterisan korišćenjem SEM i TGA/DTG analize. Naša hipoteza je bila da ako se ovaj EPS može koristiti kao potencijalni biomaterijal, onda se može primeniti za uklanjanje nikla iz kontaminirane vode. Nakon eksperimenata biosorpcije, efikasnost uklanjanja Ni2+ jona iz vodenog rastvora bila je 92,96%. Prema ovim rezultatima, ovaj egzopolisaharid se može smatrati veoma perspektivnim biomaterijalom za primenu u različitim industrijama, od farmacije do tretmana kontaminirane vod

Characterization and biological activity of exopolysaccharide extracted from novel probiotic strain L. reuteri B2., as novel biomaterial

Probiotics as the most promising group of microbes have the possibility to synthesize metabolites, that can be used in different industries over the world. In this study, we investigated the probiotic activity of the Lactobacillus reuteri B2, as well as, the exopolysaccharides (EPS) that this strain produced. L. reuteri B2 was isolated from the feces of C57BL/6 mice and assessed on probiotic activity. L. reuteri B2 was identified by 16S rDNA sequencing, in which the cell viability in acidic conditions at pH 2.0 was 64% after 2 h, and in the presents of 0.30% of the bile salts, after 6 h, was 37%. Antimicrobial assay with L. reuteri B2 showed maximum diameters against K. oxytoca J7 (12.5±0.71mm). We further hypothesized if L. reuteri B2 strain in the free form can survive all conditions in the gastrointestinal tract (GIT) then the utilization of the appropriate biomaterials would ameliorate its stability and viability in GIT. L. reuteri B2 was microencapsulated into sodium alginate- (Na-alg) and different content of Na-alg and sodium maleate (SM) beads. Second hypothesis was if a novel EPS, extracted and isolated from L. reuteri B2, that obtain biological activity can be used as biomaterial. Characterization of this EPS enveloped FTIR, NMR, SEM, XRD, TGA/DTG analysis, biological assays, antioxidative activity, cytotoxic assay (MTT), and adhesion assay of L. reuteri B2 to HT29 cells. This EPS obtained a high scavenging effect of 76% at 2mg/mL of EPS in ABTS assay, while in MTT assay showed that did not have a cytotoxic effect

Life cycle assessment and use of natural resources

In the modern era, human society consumes more natural resources than ever before. Increasing demands for energy, food, water, metals, and other natural resources have resulted in resource depletion, environmental pollution, and nature destruction. It is necessary to establish different sustainable approaches to define these effects on the environment. Life Cycle Assessment as an analytical approach can provide a determination of environmental impacts as a consequence of the use of natural resources. The aim of this study is to highlight the significance of life cycle assessment and reveal how it is connected to sustainable issues in the use of natural resources

ASSOSIATION BETWEEN PARAMETERS OF MINERAL BONE METABOLISM AND SURVIVAL IN PATIENTS UNDERGOING CHRONIC HEMODIALYSIS

Beside the traditional risk factors which have an effect on cardiovascular diseases, hemodialysis patients are exposed to metabolic factors, such as malnutrition, microinflammation and oxidative stress, along with mineral bone disorder. The aim of this study was to determine a three-year survival in patients undergoing chronic hemodialysis and to analyse correlation with parameters of mineral bone metabolism. During the three-year follow-up 186 patients were included, of which 115 men (61.83%) and 71 women, with a mean age 61.47±12.42. The exact date and the direct cause of death were recorded and mineral bone metabolism parameters were analysed. Out of 67 dead patients, 33 (49.25%) died from cardiovascular cause. Out of the total number of deaths in our study, only 11.9% of patients had a target PTH values. Patients with PTH>600 pg/ml are exposed to an increased risk from the overall mortality (RR=0.48, 95% CI (0.24-0.95), p=0.04), but also from cardiovascular mortality (RR=0.34, 95% CI (0.12-0.93), p=0.034) compared to patients with normal serum PTH. These patients have a statistically significant higher serum phosphorus in comparison with patients with normal PTH levels (1.72±0.42 vs. 1.39±0.36, p=0.032). Phosphorus above 2.10 mmol/L increases the relative risk for the overall mortality rate by 60% (RR=0.59, 95% CI (0.35-0.89), p=0.049). In our study, 2-fold higher risk of all-cause mortality (RR=2.00, 95% CI (0.92-4.36), p=0.048), and even 3-fold higher risk of cardiovascular mortality (RR=3.03, 95% CI (0.71-1.29), p=0.039) were found in patients with CaxP levels above 4.50 mmol2/L2. Three-year mortality rate of patients undergoing hemodialysis was 36.02%, while half of the patients died from cardiovascular disease. Patients with hyperparathyroidism and elevated calcium phosphorus product are at the highest risk, both for all-cause and cardiovascular mortality. Patients with hyperphosphatemia are at higher risk for all-cause mortality

Kinetic and thermodynamic compensation phenomena in C3 and C4 energy crops pyrolysis: Implications on reaction mechanisms and product distributions

This work provides insight into possibilities of maximum utilization of C3-C4 energy crops for thermo-chemical conversion (slow pyrolysis) into high value biochemicals, platform chemicals, drop-in fuels and combustible gases, using coupled kinetic and thermodynamic analyses. In order to examine the kinetics of decomposition of lignocellulosic components, model-free and model-based methods faded from thermal analysis data were used. Thermodynamic compensation was used for explicatory of entropy controlled process, where conformational changes and chemical exchange directly affect the type and distribution of obtained pyrolytic products. It was shown that external variable (i.e. the heating rate/temperature) does not change either an entire reaction mechanism (mechanistic nature of MG and AD pyrolyses) or transition state, but it changes activation enthalpy and activation entropy which lead to differences in terms of heat energy consumption, pyrolysis favorability and thus rates of generation of activated complex among feedstocks. To investigate the interplay of catalysts (present in feedstocks as minerals) and reactants, selective energy transfer (SET) model was applied. The model showed an activity of catalyst with different outputs towards two reactants, lignin part of the structure in MG and 1,8-cineole in AD. It was shown that AD is more convenient for thermal conversion than MG, regarding to lower transformation energy requirement, higher reactivity, as well as much faster accumulation of products

Thermodynamic study on energy crops thermochemical conversion to increase the efficiency of energy production

The actual paper analyses the performance of different energy crop biomasses, Miscanthus x giganteus Greef et Deu (EC-1) and Arundo donax L. (EC-2) stems, during slow pyrolysis process monitored by simultaneous TG-DTG-MS techniques, through chemical exergy analysis. In addition to considering the physical and chemical characteristics of given feedstocks for their efficient thermo-chemical conversion into pyrolytic gas, in this study, a theoretical simulation for their implementation use in the gasification process was also performed. The performed thermodynamic study with detailed exergy analysis showed that the large contribution of exergy in syngas components such as CO and H2 originates primarily from cellulose pyrolysis of EC-1, while large exergy contribution in syngas component as CH4 originates from lignin pyrolysis of EC-2. It was founded that the exergy efficiency of syngas for EC-1 equals 19.04%, which is lower than the exergy efficiency of syngas for EC-2 (20.46%), as a result of higher ash content in EC-1. Also, it was reported that higher carbon (C) and hydrogen (H) contents present in the EC-2 sample generate higher gaseous energy and exergy values, i.e. the increment of exergy efficiency of syngas, by both approaches (pyrolysis and gasification exergy analysis), but results in a lower biomass chemical exergy (18.28 MJ kg−1). The methodology applied to the gasification process was shown a higher exergy efficiency for EC-2 (∼36 – 42%) than for EC-1 (∼33 – 39%), dependant on the equivalence ratio (ER)