Food and mental possibilities

Znanstvenici dokazuju da ono što je u hrani koju jedemo može utjecati na kemijski sastav i funkciju našeg mozga i naše raspoloženje. Prehrana može utjecati na naše mentalne sposobnosti, uključujući i našu budnost te na našu sposobnost promijene proizvodnje ili otpuštanja neurotransmitera, kemijskih glasnika koji nose informacije od jedne živčane stanice do druge. Hrana se sastoji od više nego jednog nutrijenta i kako ti različiti nutrijenti međusobno reagiraju utjecat će na proizvodnju i otpuštanje neurotransmitera. Konzumacija nutrijenata (biološki aktivne tvari), u obliku hrane, utječe na kemiju tijela koja, pak, utječe na kemiju mozga i njegovu funkciju. Živčani impulsi uglavnom su rezultat razmjene natrija i kalija, ali i brojne druge tvari kao minerali (željezo, cink, selen), složeni ugljikohidrati, aminokiseline (triptofan i tirozin), masne kiseline, posebice omega - 3 masne kiseline, proteini, vitamini, posebice vitamini B6, B12 i folna kiselina, i kombinacija vitamina A, C, D i E i antioksidansi poput kvercetina, utječu na propusnost stanične membrane, metabolizam neurotransmitera i glija stanica koje pružaju strukturnu i prehrambenu podršku neuronima. Osjetljiva kemijska ravnoteža u mozgu donekle je zaštićena krvno - moždanom barijerom koja ograničava ulazak određenih kemikalija u mozak putem krvi. Ipak, mozak je vrlo osjetljiv na promjene u kemiji tijela koje proizlaze iz unosa nutrijenata i njihovih nedostataka. Mozak prima, pohranjuje i integrira senzorske informacije te inicira i nadzire motoričke reakcije. Ove funkcije odgovaraju mentalnim aktivnostima i čine temelj za čovjekovo ponašanje. Dakle, postoji izravna veza između prehrane, funkcije mozga i ponašanja.Scientists are proving that what is in the foods we eat can affect the chemical composition of our brain and our mood. Nutrition can affect our cognitive possibilities, including our alertness and our ability to alter the production or release of neurotransmitters, the chemical messangers that carry information from one nerve cell to another. Foods are made up of more than one nutrient, and how these different nutrients interact will affect the production and release of neurotransmitters. The consumption of nutrients (biologically active chemicals), in the form of foods, affects body chemistry which, in turn, affects brain chemistry and function. Neural impulses are largely the result of sodium and potassium exchange, but numerous other such as minerals (iron, selenium and zinc), complex carbohydrates, amino acids (tryptophan and tyrosine), fatty acids, particularly omega - 3 fatty acids, proteins, vitamins, notably vitamins B6, B12, and folic acid, and combination of vitamins A, C, D and E and antioxidants such as quercetin, affect cell membrane permeability, neurotransmitter metabolism and the glial cells that provide structural and nutritional support to neurons. The delicate chemical balance of the brain is somewhat protected by the blood – brain barrier, which restricts entry of certain chemicals to the brain via the blood. Nevertheless, the brain is highly susceptible to changes in body chemistry resulting from nutrient intake and deficiency. The brain receives, stores and integrates sensory information and initiates and controls motor responses. These functions correspond to mental activities and form the basis for behaviour. Thus, theoretically, there is a direct connection between nutrition, brain function and behaviour

Synthesis, characterization and application of silver nanoparticles on a macroporous polymer support.

U ovoj doktorskoj disertaciji prikazan je postupak dobijanja nanočestica srebra (Ag) na umreženom makroporoznom kopolimernom nosaču poli(glicidilmetakrilatu-ko-etilenglikol dimetakrilatu) (poli(GMA-ko-EGDMA))...In this doctoral dissertation is provided a method of obtaining silver (Ag) nanoparticles on a crosslinked macroporous copolymer support poly(glycidylmethacrylate-co-ethyleneglycol dimethacrylate) (poli(GMA-co-EGDMA))..

Influence of Geomorphology and Land Use on Soil Formation – Case Study Maksimir (Zagreb, Croatia)

Factors of soil formation govern soil processes and determine soil properties. The aim of this study was to asses the influence of geomorphology (soil parent material, soil age, soil landscape position) and land use (vegetation) on soil properties in the southeastern part of the Maksimir district in Zagreb, Croatia. Representative profiles of Eutric Cambisol, Humofl uvisol, and Pseudogley soils (soil profiles P-1, P-2, and P-3, respectively) were studied on different parent materials (older Holocene sediments, younger fluvial sediments, and loess derivates, respectively), landscape positions (lowland, lowland next to the stream, and plateau, respectively), and land uses (abandoned plough land, urban park, and forest, respectively). Geomorphology influenced soil morphological properties (horizonation, structure and consistence, redoximorphic features), soil particle size distribution (including the coarse/fine sand ratio and the vertical trends of the silt/clay ratio), and soil chemical properties (pH and ΔpH, CaCO3 content). Land use (vegetation) primarily influenced the topsoils of the investigated profiles (soil structure, abundance of roots, humus content, and soil pH), but also the presence of artefacts in the profile P-1 and the properties of redoximorphic features in the profi le P-3. Soil profi les P-1, P-2, and P-3 were classified according to the WRB-2014 system as Eutric Relictigleyic Cambisol (Geoabruptic, Loamic), Calcaric Endogleyic Fluvisol (Loamic), and Dystric Retic Stagnosol (Loamic), respectively. We conclude that both geomorphology and land use had crucial impacts on soil formation in the southeastern Maksimir. Moreover, the recent regulations of the local streams significantly influenced properties of the profiles P-1 and P-2

Surface plasmon resonance of Ag organosols: Experimental and theoretical investigations

The aim of this paper is to investigate and compare the changes in surface plasmon resonance (SPR) of silver (Ag) hydrosol and organosols obtained by experimental and theoretical approaches. Silver nanoparticles (Ag NPs) of 5 ± 1.5 nm in diameter were prepared in water by reduction of silver nitrate with sodium borohydride. Nanoparticles were subsequently transferred into different organic solvents (chloroform, hexane, toluene, 1,2-dichlorobenzene) using oleylamine as a transfer agent. These solvents were chosen because of the differences in their refractive indices. Using UV-Vis absorption spectrophotometry and transmission electron microscopy (TEM), we confirmed that there were no shape and size changes of the nanoparticles upon the transfer to the organic phase. The absorption spectra of the obtained Ag organosols showed only changes in the position of SPR band depending on dielectric property of the used solvent. To analyze these changes, absorption spectra were modelled using Mie theory for small spherical particles. The experimental and theoretical resonance values were compared with those predicted by Drude model and its limitations in the analysis of absorption behavior of Ag NPs in organic solvents were briefly discussed

Kinetic aspects of silver ions release from Ag-poly (N-isopropylacrylamide/itaconic acid) hydrogel nanocomposites

In recent years, drug delivery systems have been one of the most investigated solutions for safer and more efficient therapy. Among many investigated materials, hydrogels with incorporated drugs and/or active substances can be produced in different ways to meet the criteria of biocompatibility, non-toxicity, continuous drug delivery, etc. In our previous work, the AgP(NiPAAm/IA) hydrogel nanocomposites were produced by radiolytic method, which enabled the synthesis and sterilization of materials in one technological step. Because of silver ions release, these hydrogel nanocomposites showed good antibacterial potential against both grampositive and gram-negative bacteria. In this study, we go a step forward and investigate the silver release mechanism by fitting experimentally obtained data with several commonly used kinetics models of drug release

Brain food: how nutrition alters our mood and behaviour

Studies have been showing the food we eat affects chemical composition of our brain and alters our mood. Nutrition affects cognitive possibilities, including alertness and the production or release of neurotransmitters, the chemical messengers that carry information from one nerve cell to another. Foods are made up of more than one nutrient, and their interaction is going to affect the production and release of neurotransmitters. Neural impulses are largely resulting from sodium-potassium exchange, but numerous others such as complex carbohydrates, amino acids (tryptophan and tyrosine), fatty acids, particularly omega-3 fatty acids, affect permeability of cell membrane, neurotransmitter metabolism and glial cells. The delicate brain chemical balance is somewhat controlled by the blood – brain barrier. Still, brain remains highly susceptible to changes in body chemistry resulting from nutrient intake and deficiency. The direct connection between nutrition, brain function and behaviour exists, without any doubt. It can be seen through brain’s capability of receiving, storing and integrating sensory information, while initiating and controlling motor responses. These functions correspond to mental activities and form the basis for our behaviour. Constant rise in number of evidence from epigenetic studies confirms that specific nutrients alter our brain development and susceptibility to diseases. Still, specific combination of foods can be extrapolated to a dietary regime, like the Mediterranean diet which has shown its positive impact on maintaining brain function and lower incidence of neurodegenerative diseases. This is of special importance since elderly population (people of 65 years and older) is on the rise all over the world, and the quality of life becomes a priority

Controlled synthesis and optical properties of Ag nanoparticles

Nanosized hydrophobic, oleylamine stabilized silver (Ag) organosols were obtained in the reaction between the related metal salt and oleylamine in various organic solvents. The obtained hydrophobic colloids are stable and retain same particles morphology even after solvent evaporation and redispersion of the dried deposit in chloroform. The sizes of the Ag nanoparticles can be controlled from 8 to 25 nm by reaction temperatures. The position and shape of the surface plasmon resonance band depends upon the size and shape of Ag nanoparticles as well as dielectric constant of the medium

The effect of silver nanofillers on the thermal properties of polystyrene

Nanocomposites (NCs) comprised of metal nanoparticles (NPs) embedded in polymer matrices usually exhibit a simple combination of the physical properties of the polymer, along with the specific optical or electrical characteristics associated with the NPs. However, novel behavior can arise thanks to synergistic effects between the NPs and polymer matrix. The present work represents the continuation of our study on the interaction between silver nanoparticles (Ag NPs) and polystyrene (PS) matrix that govern the properties of polymer. Namely, in order to achieve homogeneous distribution of Ag NPs in the PS matrix, the in situ bulk radical polymerization of styrene was performed in the presence of monodisperse surface modified Ag NPs. The influence of the presence of Ag NPs and their concentration on the glass transition temperature and thermal stability of PS matrix was investigated in details using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) performed in argon and air atmosphere. The results indicated that thermal and thermo-oxidative stability of PS were improved upon incorporation of Ag NPs. The Ag/PS NCs have lower glass transition temperatures than neat PS because loosely packed oleylamine molecules at the interface caused the increase of free volume and chain segments mobility near the surface of Ag NPs

Uticaj oblika nanočestica srebra na fizičkohemijska svojstva poli(n-izopropilakrilamid) hidrogel nanokompozita

Hydrogels have unique properties and many potential applications, particularly in medicine and biotechnology. Gel porosity and swelling properties, stability, and biocompatibility are charac-teristics that are widely variable and easily adjusted. Stimuli-responsive or intelligent hydrogels are a class of thesematerials that shows a significant response to small changes in the surrounding environment. Poly(N-isopropylacrylamide) (PNiPAAm) is the best-known thermosensitive polymer with a well-defined volume phase transition temperature (VPTT) around 32C. On theother hand, silver nanoparticles (AgNPs) have been the subject of intense interest due to their size-dependent optical, catalytic, and electronic properties as well as remarkable antimicrobial potential. Within the last decade, scientists have demonstrated that anisotropic AgNPs can be synthesized in a controlled manner and that these materials exhibit distinctively different physicochemical properties from their spherical counterparts. A significant challenge that scientists face is establishing how thesenanoparticles can be used in a wider spectrum of practical applications. Therefore, we pre-sent a simple, straightforward two-step synthesis of AgNPs/PNiPAAm hydrogel nanocomposites that includes the chemical formation of both spherical and triangular AgNPs, followed by gamma irradiation-induced PNiPAAm crosslinking in the presence of nanoparticles. The gamma irradia-tion technique merges sterilization and synthesis in a single technological step, optimizing the pro-cess and opening up a wide range of innovative biomedical applications. The formation of stable and uniformly distributed AgNPs in the polymer was confirmed by UV-VIS spectroscopy, while the network porous sponge-like structure was observed by SEM analysis. Physicochemical characteri-zation was performed by examining the swelling and deswelling processes in water at 25C and 48C, respectively. In addition, AgNPs were shown to have an effect on VPTT values. Our main goal is to investigate how different morphologies of AgNPs affect the physicochemicalproperties of nanocomposite samples, considering the potential applications and the ongoing need for the wide-spread use of biocompatible materialsHidrogelovi su materijali koji poseduju specifičnu poroznost, stabilnost, biokompatibilnost i sposobnost apsorpcije okolne tečnosti, kao i svojstva koja su promenljiva i lako podesiva širokom spektru primena, naročito u oblasti medicine i biotehnologije. Posebno je interesantna oblast “inteligentnih“ hidrogelova, odnosno materijala koji reaguju na spoljašnje stimulanse i pokazuju značajanu fizičku ili hemijsku promenu pri malim promenama u okruženju. Poli(N-izopropilakrilamid) (PNiPAAm) je najpoznatiji termosenzitivni polimer sa jasno definisanom temperaturom faznog prelaza (VPTT) od oko 32°C. S druge strane, nanočestice srebra (AgNPs) poseduju optička, katalitička i električna svojstva koja se mogu modifikovati promenom njihove veličine i oblika a imaju i izražen antibakterijski potencijal, pa su stoga, poslednjih decenija intenzivno proučavane. Pokazano je da se anizotropne nanočestice srebra mogu kontrolisano sintetisati sa fizičkohemijskim svojstvima različitim od sfernih analoga, pri čemu su značajna istraživanja usmerena na njihovu praktičnu primenu. Zbog svega navedenog, u okviru ovog istraživanja biće izvedena jednostavna dvostepena sinteza AgNPs/PNiPAAm hidrogel nanokompozita koja uključuje hemijsko formiranje sfernih i trouglastih AgNPs u prvom koraku, a zatim gama-indukovano umrežavanje NiPAAm-a u prisustvu ovih AgNPs. Tehnika gama zračenja objedinjuje sterilizaciju i sintezu u jednom tehnološkom koraku čime se proces optimizuje i otvara širok spektar inovativnih biomedicinskih primena. Formiranje stabilnih i uniformno distribuiranih AgNPs unutar matrice hidrogela potvrđeno je UV-Vis spektroskopijom, a porozna sunđerasta struktura polimerne mreže SEM analizom. Fizičkohemijska karakterizacija izvršena je i ispitivanjem procesa bubrenja i kontrahovanja u vodi na 25°C i 48°C, redom. Pored toga, pokazano je da prisustvo AgNPs utiče na vrednosti temperature faznog prelaza polimera. Osnovni cilj ovog istraživanja je ispitivanje uticaja različite morfologije AgNPs na fizičkohemijska svojstva sintetisanih nanokompozita, imajući u vidu njihovu potencijalnu primenu i stalnu potrebu za širokom upotrebom biokompatibilnih materijala.36. Međunarodni kongres o procesnoj industriji - PROCESING ′23 : zbornik radova ; 1-2. jun, Šaba