Fotonska i elektronska akciona spektroskopija trapiranih biomolekularnih jona - od izolovanih do nanosolvatisanih čestica

In an effort to understand the vast complexity of the underlying processes within a cell at a molecular level, the first step lies in revealing the fundamental physical and chemical properties, as well as the structure, of biopolymers (proteins and DNA). With the development of modern experimental techniques it has become possible to study these large molecules under well-defined conditions in the gas phase, by closely inspecting their interactions with energetic photons and electrons. In this Thesis, we present the experimental setups for the action spectroscopy of peptides, proteins and nucleotides, as well as the hydrated complexes (hydrated nucleotides), in the gas phase. We present the details and the operation of the two experimental setups based on coupling the linear quadrupole ion trap with: (1) a VUV or a soft X-ray synchrotron beamline and (2) a focusing electron gun. In the case (1), the existing experimental setup consisting of a commercial quadrupole ion trap mass spectrometer (LTQ XL from Thermo Scientific), equipped with an electrospray ion source, was coupled to the VUV beamline DESIRS and the soft X-ray beamline PLEIADES at the synchrotron SOLEIL (France). The setups were used to study the photo-induced ionization/fragmentation of trapped biopolymers and nanosolvated species. The results obtained with this setups include VUV action spectroscopy of protonated Leucine-Enkephalin peptide (both a monomer and a dimer) and a nanosolvated nucleotide Adenosine monophosphate (AMP), in (5-15) eV photon energy range. The inner-shell action spectroscopy in the soft X-ray energy range (around C and N K-edge), was performed for multiply charged precursor of Ubiquitin protein. The photo-dissociation and photo-fragmentation ion yields for several fragment ions from all above mentioned macromolecules were extracted and the obtained spectral features were discussed considering relevant photon-induced processes. In the case (2), new experimental setup was developed by coupling the same LTQ XL ion trap with a focusing electron gun, in order to perform an electron activation tandem mass spectrometry, as well as an electron-impact action spectroscopy of trapped biopolymer ions. The ion optic simulations using SIMION program were performed in order to investigate the propagation of the electron beam in the RF+DC ion trap. Tests measurements for electron-induced fragmentation of Substance P, Melittin and Ubiquitin are presented for the impact energy of 300 eV. Finally, we present the electron-impact inner-shell action spectroscopy of the multiply charged Ubiquitin protein, in the vicinity of C K-edge energies of (280-300) eV. The electron-impact results are compared with the soft X-ray photon-impact action spectroscopy results obtained for the same target.U nastojanju da se razume ogromna složenost procesa u okviru ćelije na molekulskom nivou, prvi korak je otkrivanje fundamentalnih fizičko-hemijskih osobina, kao i strukture biopolimera (proteina i DNK). Razvojem savremenih eksperimentalnih tehnika omogućeno je proučavanje velikih biološki relevantnih molekula pod jasno definisanim uslovima u gasnoj fazi, izučavanjem njihovih interakcija sa fotonima i elektronima velikih energija. U ovom radu su predstavljene eksperimentalne postavke za akcionu spektroskopiju peptida, proteina, nukleotida, kao i nanosolvatisanih kompleksa (hidratisani nukleotidi) u gasnoj fazi. Prikazani su detalji i princip rada dve eksperimentalne postavke zasnovane na povezivanju linearne kvadrupolne jonske zamke sa: (1) sinhrotronskim fotonskim mlazom (VUV i meki X-zraci) i (2) fokusirajućim elektronskim topom. U slucaju (1), postojeća eksperimentalna aparatura koja sadrži linearnu kvadrupolnu jonsku zamku u okviru komercijalnog masenog spektrometra (LTQ XL od firme Thermo Scientific) povezana je sa VUV mlaznom linijom DESIRS i mlaznom linijom za meke X-zrake PLEIADES na sinhrotronu SOLEIL (Francuska). Aparatura je upotrebljena za izučavanje foto-indukovanih procesa jonizacije i fragmentacije zarobljenih jona biopolimera i nanosolvatisanih čestica. Rezultati dobijeni na ovoj aparaturi uključuju VUV akcionu spektroskopiju protonisanog leucin-enkefalin peptida (monomer i dimer), kao i nanosolvatisanog nukleotida adenosin monofosfata (AMP), u opsegu energija fotona od (5-15) eV. Akciona spektroskopija unutrašnje ljuske koristeći meke X-zrake (u oblasti C i N K-ljuske), urađena je za višestruko naelektrisani prekursor proteina ubikuitin. Za sve gore pomenute makromolekule, izučavani su absorpcioni spektri za neke od dobijenih jonskih produkata, pri čemu su analizirane uočene spektralne karakteristike dobijene u pomenutim fotonski indukovanim procesima. U slucaju (2) razvijen je novi eksperimentalni sistem zasnovan na povezivanju iste LTQ XL jonske zamke sa elektronskim topim sa mlazom elektrona srednjih energija, koja omogućava tandem masenu spektrometriju i elektronski indukovanu akcionu spektroskopiju zarobljenih jona biopolimera. Korišćenjem programa SIMION, urađene su simulacije sa ciljem ispitivanja transmisije elektrona kroz jonsku zamku sa RF+DC potencijalima. Inicijalni testovi aparature uradjeni su fragmentacijom peptida supstance P i melitin, kao i ubikuitin proteina pri energijama elektrona u oblasti oko 300 eV. Na kraju, prikazani su rezultati elektronski-indukovane akcione spektroskopije višestruko naelektrisaniog jona ubikuitin proteina, u oblasti energija oko C K-ljuske (280-300) eV. Ovi rezultati su upoređeni sa rezultatima dobijenim za istu metu pri fotonskiindukovanim (X-zraci) procesima iz iste oblasti energija

Arterijska vaskularizacija amigdale psa

We investigated the vascularization of the amygdala of the dog using various contrast agents injected into the internal carotid and vertebral artery. Subsequent clearance of the tissues gives us an opportunity to study the finest capillary network in the amygdala. The corticomedial part of the amygdala has a good vascularization given by the rostral and caudal choroid arteries. The rostral choroid gives off a rich capillary net to the nucleus centralis (NCE), its pars lateralis (NCEL) and pars medialis (NCEM). Nucleus medialis (NM) is poorly vascularized compared to the central nuclei. The massa intercalata (MI) also has a delicate artery around which there is a fine net of capillaries. Nucleus corticalis (NCO) and area enthorhinalis (AER) are better vascularized by the subpial blood vessel. The caudal choroid, a branch of the caudal cerebral artery is a source of subpial capillaries. The basolateral part of the amygdala is very well vascularized by the rostral choroid artery, a branch of the middle cerebral, especially the nucleus basolateralis (NBL) and nucleus lateralis posterior (NLP). The nucleus basomedialis (NBM) is poorly vascularize by the rostral choroid artery . The amygdala, is served by the middle cerebral artery, via its branch, the rostral choroid, and the caudal cerebral artery via its branch the caudal choroid artery. Every amygdala nucleus has its own central artery around which is formed a rich net of capillaries.Proučavanje vaskularizacije amigdale psa vršeno je upotrebom različitih kontrasnih sredstava injiciranih u a. carotis interna i a. vertebralis a prosvetljavanje tkiva daje mogućnost da se prouči i najfinija vaskularna mreža u amigdali. Kortikomedijalni deo amigdale vaskularišu a. choroidea rostralis i a. choroidea caudalis. A. choroidea rostralis, daje bogatu mrežu kapilara u NCE (nucleus centralis) i njegovom lateralnom i medijalnom delu (NCEL i NCEM). Nucleus medialis (NME) je slabije vaskularisan u poredjenju sa vaskularizacijom NCE. Massa intercalata (MI) je takodje snabdevena bogatom mrežom kapilara. A. choroidea caudalis, kao subpialna arterija, vaskulariše NCO (nucleus corticalis) i AER (area enthorhinalis). Bazolateralni deo amigdale vaskulariše samo a. choroid rostralis. Bogata mreža kapilara uočava se u NBL (nucleus basolateralis) i NLP (nucleus lateralis posterior) a nešto siromašnija u NBM (nucleus basomedialis). Krv u amigdalu dovode dve arterije: a. choroidea rostralis, grana od a. cerebri media, i a. choroidea caudalis, grana od a. cerebri caudalis. Svaki nukleus amigdale ima svoju centralnu arteriju i oko nje jako razvijenu mrežu kapilara

Resonances in nitrobenzene probed by the electron attachment to neutral and by the photodetachment from anion

We probe resonances (transient anions) in nitrobenzene with the focus on the electron emission from these. Experimentally, we populate resonances in two ways: either by the impact of free electrons on the neutral molecule or by the photoexcitation of the bound molecular anion. These two excitation means lead to transient anions in different initial geometries. In both cases, the anions decay by electron emission and we record the electron spectra. Several types of emission are recognized, differing by the way in which the resulting molecule is vibrationally excited. In the excitation of specific vibrational modes, distinctly different modes are visible in electron collision and photodetachment experiments. The unspecific vibrational excitation, which leads to the emission of thermal electrons following the internal vibrational redistribution, shows similar features in both experiments. A model for the thermal emission based on a detailed balance principle agrees with the experimental findings very well. Finally, a similar behavior in the two experiments is also observed for a third type of electron emission, the vibrational autodetachment, which yields electrons with constant final energies over a broad range of excitation energies. The entrance channels for the vibrational autodetachment are examined in detail, and they point to a new mechanism involving a reverse valence to non-valence internal conversion

Sortiment i uzgojnih oblika kao uticajni faktori energetskog potencijala rezidbenih ostataka iz voćarsko-vinogradarske proizvodnje

Biomass resulting from agricultural production represents potential which can be used in multiple ways. The expansion of fruit-growing and viticulture in Serbia in recent years contributes to an even larger quantities of pruning residues. Long-standing practice of destroying and burning of the pruning residues hardly changed, but the energy and environmental indicators point to the importance of proper exploitation of this biomass. The aim of this study is to show the quantity and energy value of tree branches from fruitgrowing and viticulture as fuel, as well as the influence of different fruit types and vine varieties and training systems on energy potential. The apple sort Idared has the highest values of thermal power per mass unit (19.853 kJ kg-1) and the peach sort Redheven has the highest value of thermal power per area unit (974,78 GJ ha-1). The grapevine lags behind other sorts of fruit have significantly less thermal power per unit, but the calorific value per unit mass ranges within the limits of 17,300 ± 100 kJ kg-1.Biomasa iz poljoprivredne proizvodnje, predstavlja nedovoljno iskorišćen potencijal. Ekspanzija voćarske i vinogradarske proizvodnje u Srbiji, poslednjih godina, doprinosi stvaranju ogromnih količina rezidbenih ostataka. Dugogodišnja praksa uništavanja i spaljivanja rezidbenih ostataka se polako menja, ali energetski i ekološki pokazatelji ukazuju na značaj pravilnog korišćenja ove biomase. Cilj ovog rada je da prikaže količine i energetsku vrednost rezidbenih ostataka iz voćarske i vinogradarske proizvodnje, kao i uticaj različitih voćnih vrsta, sorti vinove loze i uzgojnih oblika na energetski potencijal. Najveću toplotnu moć po jedinici mase ustanovljeno je kod jabuke sorte Ajdared (19.853 kJ kg-1), a najveću toplotnu moć po jedinici površine ostvarena je kod breskve, sorte Redheven (974,78 GJ ha-1). Vinova loza u odnosu na voćne vrste ima značajno manju toplotnu moć po jedinici površine, dok se toplotna moć po jedinici mase kreće oko 17.300 ± 100 kJ kg-1

Mehanizovani postupci pripreme i obrade komposta od rezidbenih ostataka voćarsko-vinogradarske proizvodnje

This paper is part of research about the effects of mechanized process of fragmentation of pruning residues on the composting process. Compost, as a form of organic fertilizer, requires specific production treatment depending on the form of biomass. Pruning residues from fruit-vine production can be translated into quality organic fertilizer, but it is necessary to coordinate mechanized treatment of biomass and technology of composting process with microbiological processes for organic matter decomposition.Rad predstavlja deo istraživanja uticaja mehanizovanih procesa usitnjavanja rezidbenih ostataka na proces kompostiranja. Kompost kao vid organskog đubriva zahteva specifičan tretman proizvodnje u zavisnosti od vida biomase. Rezidbeni ostaci iz voćarsko-vinogradarske proizvodnje se mogu prevesti u kvalitetno organsko đubrivo, ali je potrebno uskladiti mehanizovane procese obrade biomase i tehnologiju kompostiranja sa mikrobiološkim procesima razlaganja organske materije

Uticaj vrste filtera na kvalitet određivanja rastvorljivosti “shake-flask” metodom

The aim of the present study was to examine the influence of the filter type during phase separation on solubility determination. Polyether sulfone (hydrophobic) and polyvinylidene fluoride (hydrophilic) filters were chosen. The concentration was measured by UV/Vis spectrophotometry. Carvedilol (base) and ibuprofen (acid) are used as a model compounds. LogP values were determined by miniaturized shake-flask method and by optimized potentiometric titration. It is shown that solubility data can be influenced by membrane filter type which is used for filtration, after the equilibrium is established during dissolution. Magnitude of this influence depends of lipophilicity and pKa value of molecule and a solution pH value.Cilj ovog rada je ispitivanje uticaja vrste membrane filtera u procesu odvajanja faza pri određivanju rastvorljivosti „shake-flask“ metodom. Izabrani su polietar-sulfon (hidrofobni) i poliviniliden-fluorid (hidrofilni) filteri. Koncentracija je merena pomoću UV/Vis spektrofotometrije. Kao model supstance korišćeni su karvedilol (baza) i ibuprofen (kiselina). Minijaturizovanom „shake-flask“ metodom i optimizovanom metodom potenciometrijske titracije određene su i logP vrednosti. Pokazano je da rezultat određivanja rastvorljivosti može zavisiti od vrste membrane filtera koji se koristi za odvajanje filtrata nakon uspostavljanja ravnoteže u rastvoru tokom rastvaranja. Jačina uticaja zavisi od lipofilnosti i pKa vrednosti ispitavanog molekula kao i od pH vrednosti rastvora u kom se izvodi određivanje

Uticaj vrste filtera na kvalitet određivanja rastvorljivosti “shake-flask” metodom

The aim of the present study was to examine the influence of the filter type during phase separation on solubility determination. Polyether sulfone (hydrophobic) and polyvinylidene fluoride (hydrophilic) filters were chosen. The concentration was measured by UV/Vis spectrophotometry. Carvedilol (base) and ibuprofen (acid) are used as a model compounds. LogP values were determined by miniaturized shake-flask method and by optimized potentiometric titration. It is shown that solubility data can be influenced by membrane filter type which is used for filtration, after the equilibrium is established during dissolution. Magnitude of this influence depends of lipophilicity and pKa value of molecule and a solution pH value.Cilj ovog rada je ispitivanje uticaja vrste membrane filtera u procesu odvajanja faza pri određivanju rastvorljivosti „shake-flask“ metodom. Izabrani su polietar-sulfon (hidrofobni) i poliviniliden-fluorid (hidrofilni) filteri. Koncentracija je merena pomoću UV/Vis spektrofotometrije. Kao model supstance korišćeni su karvedilol (baza) i ibuprofen (kiselina). Minijaturizovanom „shake-flask“ metodom i optimizovanom metodom potenciometrijske titracije određene su i logP vrednosti. Pokazano je da rezultat određivanja rastvorljivosti može zavisiti od vrste membrane filtera koji se koristi za odvajanje filtrata nakon uspostavljanja ravnoteže u rastvoru tokom rastvaranja. Jačina uticaja zavisi od lipofilnosti i pKa vrednosti ispitavanog molekula kao i od pH vrednosti rastvora u kom se izvodi određivanje

The effect of the filter type on the quality of “shake flask” solubility determinations

Određivanje rastvorljivosti je važno u svim fazama razvoja leka. Dobijeni podaci se koriste za nalaženje potencijalnih lekova-kandidata, biofarmaceutsku klasifikciju i optimizaciju formulacije leka. Na merenje rastvorljivosti utiču različiti faktori: vreme mešanja, vreme sedimentacije, sastav pufera, temperatura, višak čvrste faze i tehnika odvajanja faza.[1] Cilj ovog rada je ispitivanje uticaja vrste membrane filtera u procesu odvajanja faza pri određivanju rastvorljivosti „shake-flask“ metodom. Izabrani su polietar-sulfon (hidrofobni) i poliviniliden-fluorid (hidrofilni) filteri. Koncentracija je merena pomoću UV/Vis spektrofotometrije. Kao model supstance korišćeni su karvedilol (baza) i ibuprofen (kiselina). Minijaturizovanom „shake-flask“ metodom i optimizovanom metodom potenciometrijske titracije određene su i logP vrednosti. Pokazano je da rezultat određivanja rastvorljivosti može zavisiti od vrste membrane filtera koji se koristi za odvajanje filtrata nakon uspostavljanja ravnoteže u rastvoru tokom rastvaranja. Jačina uticaja zavisi od lipofilnosti i pKa vrednosti ispitavanog molekula kao i od pH vrednosti rastvora u kom se izvodi određivanje.Solubility determination is important in both early and development phase of drug research. This data is used to screen out drug-like candidates, biopharmaceutical classification and formulation optimization. Solubility measurements are influenced by several experimental factors: stirring and sedimentation time, composition of the aqueous buffer, temperature, amount of solid excess and the technique of phase-separation.1 The aim of the present study was to examine the influence of the filter type during phase separation on solubility determination. Polyether sulfone (hydrophobic) and polyvinylidene fluoride (hydrophilic) filters were chosen. The concentration was measured by UV/Vis spectrophotometry. Carvedilol (base) and ibuprofen (acid) are used as a model compounds. LogP values were determined by miniaturized shake-flask method and by optimized potentiometric titration. It is shown that solubility data can be influenced by membrane filter type which is used for filtration, after the equilibrium is established during dissolution. Magnitude of this influence depends of lipophilicity and pKa value of molecule and a solution pH valu

Market risk management in a post-Basel II regulatory environment

We propose a novel method of Mean-Capital Requirement portfolio optimization. The optimization is performed using a parallel framework for optimization based on the Nondominated Sorting Genetic Algorithm II. Capital requirements for market risk include an additional stress component introduced by the recent Basel 2.5 regulation. Our optimization with the Basel 2.5 formula in the objective function produces superior results to those of the old (Basel II) formula in stress scenarios in which the correlations of asset returns change considerably. These improvements are achieved at the expense of reduced cardinality of Pareto-optimal portfolios. This reduced cardinality (and thus portfolio diversification) in periods of relatively low market volatility may have unintended consequences for banks’ risk exposure

Study of electron transmission through a metallic capillary

In this work we study the transmission of charged particles through a single cylindrically shaped metallic capillary of microscopic dimensions with a large aspect ratio. We used electrons as projectiles. Our results suggest the existence of guiding of the electron beam by a metallic capillary.29th International Conference on Photonic, Electronic, and Atomic Collisions (ICPEAC), Jul 22-28, 2015, Toledo, Spai