Assessment of metabolic fluxes in the mouse brain in vivo using 1H-[13C] NMR spectroscopy at 14.1 Tesla.

(13)C magnetic resonance spectroscopy (MRS) combined with the administration of (13)C labeled substrates uniquely allows to measure metabolic fluxes in vivo in the brain of humans and rats. The extension to mouse models may provide exclusive prospect for the investigation of models of human diseases. In the present study, the short-echo-time (TE) full-sensitivity (1)H-[(13)C] MRS sequence combined with high magnetic field (14.1 T) and infusion of [U-(13)C6] glucose was used to enhance the experimental sensitivity in vivo in the mouse brain and the (13)C turnover curves of glutamate C4, glutamine C4, glutamate+glutamine C3, aspartate C2, lactate C3, alanine C3, γ-aminobutyric acid C2, C3 and C4 were obtained. A one-compartment model was used to fit (13)C turnover curves and resulted in values of metabolic fluxes including the tricarboxylic acid (TCA) cycle flux VTCA (1.05 ± 0.04 μmol/g per minute), the exchange flux between 2-oxoglutarate and glutamate Vx (0.48 ± 0.02 μmol/g per minute), the glutamate-glutamine exchange rate V(gln) (0.20 ± 0.02 μmol/g per minute), the pyruvate dilution factor K(dil) (0.82 ± 0.01), and the ratio for the lactate conversion rate and the alanine conversion rate V(Lac)/V(Ala) (10 ± 2). This study opens the prospect of studying transgenic mouse models of brain pathologies.

Tratamentos hidrotérmico e com radiação UV-C no controle pós-colheita da podridão olho-de-boi em uma linha comercial de seleção de maçãs

Avaliaram-se os efeitos da aspersão hidrotérmica e da radiação UV-C no controle pós-colheita da podridão olho-de-boi (POB) em maçãs 'Fuji', após um e oito meses de armazenamento, e 'Gala', após cinco meses de armazenamento, ambas sob condição de atmosfera controlada (AC). Esses frutos foram inoculados ou mantidos com infecção natural de Cryptosporiopsis perennans. As maçãs 'Fuji' foram submetidas aos seguintes tratamentos, aplicados em uma linha comercial de seleção: sem tratamento (testemunha); aspersão hidrotérmica (água a 50ºC por 12 segundos); radiação UV-C (0,0069 kJ m-2); e aspersão hidrotérmica + radiação UV-C. As maçãs 'Gala' também foram submetidas a estes tratamentos utilizados em 'Fuji', exceto ao tratamento com aspersão hidrotérmica + radiação UV-C. Após os tratamentos, as maçãs foram incubadas a 22ºC por 15 dias e avaliadas quanto à incidência da doença. Nas maçãs 'Fuji', os tratamentos de aspersão hidrotérmica e/ou radiação UV-C reduziram a incidência da POB nos frutos inoculados e com infecção natural, proporcionando controle superior a 56% e 54%, em relação à testemunha, respectivamente. Em maçãs 'Gala' inoculadas, os tratamentos com aspersão hidrotérmica e radiação UV-C também reduziram o número de unidades formadoras de colônias (UFC) nos frutos, com controle superior a 70%, e a incidência da POB, com controle superior a 69% em relação à testemunha. Em maçãs 'Gala', com infecção natural, estes tratamentos apresentaram controle da POB superior a 85% em relação à testemunha. Os resultados obtidos mostram que os tratamentos com aspersão hidrotérmica e/ou radiação UV-C reduzem a incidência da POB em maçãs 'Fuji' e 'Gala', em linha comercial de seleção. Todavia, o uso da radiação UV-C, em ambas as cultivares, foi o tratamento que apresentou maior benefício e retorno econômico.

ZnO nanorods for efficient third harmonic UV generation.

ZnO nanorods grown by both high temperature vapour phase transport and low temperature chemical bath deposition are very promising sources for UV third harmonic generation. Material grown by both methods show comparable efficiencies, in both cases an order of magnitude higher than surface third harmonic generation at the quartz-air interface of a bare quartz substrate. This result is in stark contrast to the linear optical properties of ZnO nanorods grown by these two methods, which show vastly different PL efficiencies. The third harmonic generated signal is analysed using intensity dependent measurements and interferometric frequency resolved optical gating, allowing extraction of the laser pulse parameters. The comparable levels of efficiency of ZnO grown by these very different methods as sources for third harmonic UV generation provides a broad suite of possible growth methods to suit various substrates, coverage and scalability requirements. Potential application areas range from interferometric frequency resolved optical gating characterization of few cycle fs pulses to single cell UV irradiation for biophysical studies.

Fenólicos totais, polifenoloxidade e coloração em abacate 'Hass' submetido a radiação UV-C

Avaliou-se o efeito da radiação UV-C em abacates Hass, quanto ao conteúdo de fenólicos totais, atividade da enzima polifenoloxidase (PPO) e coloração. Os frutos selecionados foram submetidos à radiação em luz UV-C durante 5; 10; 15 e 20 minutos, sendo mantidos sob refrigeração (10 ± 1 ºC e 90±5% UR), e avaliados durante 15 dias. Para o teor fenólicos totais e PPO, não se observou diferença entre os tratamentos dos frutos nos diferentes tempos de exposição à luz UV-C. Os teores fenólicos totais e PPO diminuíram durante o período experimental. Os valores de luminosidade mantiveram-se elevados (85,4 a 88,5) no armazenamento. Os valores de cor a* e b* diminuíram com o armazenamento de forma mais intensa para os frutos submetidos à radiação UV-C. Não houve correlação significativa para a PPO, conteúdo de fenólicos totais e coloração.

Painatuksen UV-stabiilisuuden optimointi fenolihartsatussa paperissa

Tässä diplomityössä tutkittiin painetun paperin ja siitä fenoliformaldehydihartsilla impregnoimalla valmistetun pinnoituskalvon UV-stabiilisuuden parantamis-mahdollisuuksia. Työn kirjallisuusosassa käsitellään painetun pinnoituskalvon valmistusprosessia ja painatuksen UV-valonkestoon vaikuttavia tekijöitä. Painovärin pigmentti, sen määrä ja käsittely, painovärin sideaine sekä fenoliformaldehydihartsi ja sen lisäaineet vaikuttavat pinnoitetun betonoimisvanerin säänkesto-ominaisuuksiin. Erilaisilla epäorgaanisilla valkoisilla pigmenteillä ja kidemuodoilla on erilainen UV-valonkesto ja taitekerroin. Päällystämällä titaanidioksidi esimerkiksi alumiini- tai zirkoniumoksideilla sen UV-valonkestoa voidaan parantaa merkittävästi. UV-hajoaminen voidaan havaita painetun pinnoitteen liituuntumisena. Liituuntumista voidaan pitää veden ja hapen välisenä reaktiona, jota titaanidioksidi ja UV-säteily katalysoivat. Sen takia myös muiden valkoisten epäorgaanisten pigmenttien ominaisuuksia ja käyttöä selvitettiin. Kokeissa käytettiin yhdeksää eri painoväriä, kahta eri paksuista paperia ja kahta eri tyyppistä hartsia. Painovärejä ohennettiin vedellä ja paperin painopuolta vaihdeltiin. Kaikissa painatuksissa käytettiin kolmea eri rasterointiasteen laattaa, jolloin painovärin määrää paperissa saatiin vähennettyä. Painetuista papereista mitattiin densiteetti, värimäärä, pisara-absorptio vedellä ja kontaktikulma hartsilla. Myös painovärin tunkeumaa selvitettiin paperin poikkileikeistä tehtyjen SEM-kuvien avulla. Painetut paperit impregnoitiin fenoliformaldehydihartsilla kalvoksi. Pinnoituskalvot puristettiin vanerin pinnalle laboratoriopuristimella. Koekappaleet altistettiin UV-valolle, sateelle ja pakkaselle sääkaapissa 400 h ajan, mikä vastaa noin 1,5 vuotta ulkona Suomen oloissa. Kappaleista mitattiin kiilto, värinmuutos ja liituuntuminen. Pinnoitteen liituuntumista tapahtui vähiten niissä koepisteissä, joissa painatus oli tehty 30 % rasteroidulla laatallaSäänkestävä TiO2 osoittautui hyväksi, mutta myös ZnO-pigmentillä saatiin hyviä tuloksia. ZnO-koepisteessä liituuntumisreaktio ei ole niin voimakkaasti katalysoitu kuin TiO2-koepisteissä. Paksun paperin painatuspuolella näytti olevan merkitystä säänkestoon. Huopapuolelle painettuna pinnoitteen liituuntuminen oli vähäisempää

Photocontrolled DNA Binding of a Receptor-Targeted Organometallic Ruthenium(II) Complex

A photoactivated ruthenium(II) arene complex has been conjugated to two receptor-binding peptides, a dicarba analogue of octreotide and the Arg-Gly-Asp (RGD) tripeptide. These peptides can act as"tumor-targeting devices" since their receptors are overexpressed on the membranes of tumor cells. Both ruthenium-peptide conjugates are stable in aqueous solution in the dark, but upon irradiation with visible light, the pyridyl-derivatized peptides were selectively photodissociated from the ruthenium complex, as inferred by UV-vis and NMR spectroscopy. Importantly, the reactive aqua species generated from the conjugates, [(η6-p-cym)Ru(bpm)(H2O)]2+, reacted with the model DNA nucleobase 9-ethylguanine as well as with guanines of two DNA sequences, 5′dCATGGCT and 5′dAGCCATG. Interestingly, when irradiation was performed in the presence of the oligonucleotides, a new ruthenium adduct involving both guanines was formed as a consequence of the photodriven loss of p-cymene from the two monofunctional adducts. The release of the arene ligand and the formation of a ruthenated product with a multidentate binding mode might have important implications for the biological activity of such photoactivated ruthenium(II) arene complexes. Finally, photoreactions with the peptide-oligonucleotide hybrid, Phac-His-Gly-Met-linker-p5′dCATGGCT, also led to arene release and to guanine adducts, including a GG chelate. The lack of interaction with the peptide fragment confirms the preference of such organometallic ruthenium(II) complexes for guanine over other potential biological ligands, such as histidine or methionine amino acids.

Force Spectroscopy with Dual-Trap Optical Tweezers: Molecular Stiffness Measurements and Coupled Fluctuations Analysis

ABSTRACT Dual-trap optical tweezers are often used in high-resolution measurements in single-molecule biophysics. Such measurements can be hindered by the presence of extraneous noise sources, the most prominent of which is the coupling of fluctuations along different spatial directions, which may affect any optical tweezers setup. In this article, we analyze, both from the theoretical and the experimental points of view, the most common source for these couplings in dual-trap optical-tweezers setups: the misalignment of traps and tether. We give criteria to distinguish different kinds of misalignment, to estimate their quantitative relevance and to include them in the data analysis. The experimental data is obtained in a, to our knowledge, novel dual-trap optical-tweezers setup that directly measures forces. In the case in which misalignment is negligible, we provide a method to measure the stiffness of traps and tether based on variance analysis. This method can be seen as a calibration technique valid beyond the linear trap region. Our analysis is then employed to measure the persistence length of dsDNA tethers of three different lengths spanning two orders of magnitude. The effective persistence length of such tethers is shown to decrease with the contour length, in accordance with previous studies.

Measurement Problems and Problem-Solving in Kraft Pulping

Tämän työn tarkoituksena on koota yhteen selluprosessin mittausongelmat ja mahdolliset mittaustekniikat ongelmien ratkaisemiseksi. Pääpaino on online-mittaustekniikoissa. Työ koostuu kolmesta osasta. Ensimmäinen osa on kirjallisuustyö, jossa esitellään nykyaikaisen selluprosessin perusmittaukset ja säätötarpeet. Mukana on koko kuitulinja puunkäsittelystä valkaisuun ja kemikaalikierto: haihduttamo, soodakattila, kaustistamo ja meesauuni. Toisessa osassa mittausongelmat ja mahdolliset mittaustekniikat on koottu yhteen ”tiekartaksi”. Tiedot on koottu vierailemalla kolmella suomalaisella sellutehtaalla ja haastattelemalla laitetekniikka- ja mittaustekniikka-asiantuntijoita. Prosessikemian paremmalle ymmärtämiselle näyttää haastattelun perusteella olevan tarvetta, minkä vuoksi konsentraatiomittaukset on valittu jatkotutkimuskohteeksi. Viimeisessä osassa esitellään mahdollisia mittaustekniikoita konsentraatiomittausten ratkaisemiseksi. Valitut tekniikat ovat lähi-infrapunatekniikka (NIR), fourier-muunnosinfrapunatekniikka (FTIR), online-kapillaarielektroforeesi (CE) ja laserindusoitu plasmaemissiospektroskopia (LIPS). Kaikkia tekniikoita voi käyttää online-kytkettyinä prosessikehitystyökaluina. Kehityskustannukset on arvioitu säätöön kytketylle online-laitteelle. Kehityskustannukset vaihtelevat nollasta miestyövuodesta FTIR-tekniikalle viiteen miestyövuoteen CE-laitteelle; kehityskustannukset riippuvat tekniikan kehitysasteesta ja valmiusasteesta tietyn ongelman ratkaisuun. Työn viimeisessä osassa arvioidaan myös yhden mittausongelman – pesuhäviömittauksen – ratkaisemisen teknis-taloudellista kannattavuutta. Ligniinipitoisuus kuvaisi nykyisiä mittauksia paremmin todellista pesuhäviötä. Nykyään mitataan joko natrium- tai COD-pesuhäviötä. Ligniinipitoisuutta voidaan mitata UV-absorptiotekniikalla. Myös CE-laitetta voitaisiin käyttää pesuhäviön mittauksessa ainakin prosessikehitysvaiheessa. Taloudellinen tarkastelu pohjautuu moniin yksinkertaistuksiin ja se ei sovellu suoraan investointipäätösten tueksi. Parempi mittaus- ja säätöjärjestelmä voisi vakauttaa pesemön ajoa. Investointi ajoa vakauttavaan järjestelmään on kannattavaa, jos todellinen ajotilanne on tarpeeksi kaukana kustannusminimistä tai jos pesurin ajo heilahtelee eli pesuhäviön keskihajonta on suuri. 50 000 € maksavalle mittaus- ja säätöjärjestelmälle saadaan alle 0,5 vuoden takaisinmaksuaika epävakaassa ajossa, jos COD-pesuhäviön vaihteluväli on 5,2 – 11,6 kg/odt asetusarvon ollessa 8,4 kg/odt. Laimennuskerroin vaihtelee tällöin välillä 1,7 – 3,6 m3/odt asetusarvon ollessa 2,5 m3/odt.

Assessment of the discrimination of animal fat by FT_Raman spectroscopy

In recent years, there has been an increased attention towards the composition of feeding fats. In the aftermath of the BSE crisis all animal by-products utilised in animal nutrition have been subjected to close scrutiny. Regulation requires that the material belongs to the category of animal by-products fit for human consumption. This implies the use of reliable techniques in order to insure the safety of products. The feasibility of using rapid and non-destructive methods, to control the composition of feedstuffs on animal fats has been studied. Fourier Transform Raman spectroscopy has been chosen for its advantage to give detailed structural information. Data were treated using chemometric methods as PCA and PLS-DA which have permitted to separate well the different classes of animal fats. The same methodology was applied on fats from various types of feedstock and production technology processes. PLS-DA model for the discrimination of animal fats from the other categories presents a sensitivity and a specificity of 0.958 and 0.914, respectively. These results encourage the use of FT-Raman spectroscopy to discriminate animal fats.

Histologic evaluation of thermal damage produced on soft tissues by CO2, Er,Cr:YSGG and diode lasers

Objective: The aim of this in vitro experimental study was to perform histological evaluation of the thermal effect produced on soft tissue irradiated with CO2, Er,Cr:YSGG or diode lasers. Study design: Porcine oral mucosa samples were irradiated with Er,Cr:YSGG laser at 1 W with and without water / air spray, at 2 W with and without water / air spray, and at 4 W with water / air spray, with CO2 laser at 1 W, 2 W, 10 W, 20 W continuous mode and 20 W pulsed mode and diode laser at 2W, 5W, and 10W pulsed mode. The thermal effect was evaluated measuring the width of damaged tissue adjacent to the incision, stained positively for hyalinized tissue with Hematoxylin-Eosin and Masson Trichrome stains. Besides, histological changes in the irradiated tissue were described using subjective grading scales. Results: The evaluated lasers developed a wide range of thermal damage with significant differences between groups. The samples with lowest thermal effect were those irradiated with Er,Cr:YSGG laser using water / air spray, followed by CO2 and diode lasers. Conclusions: Emission parameters of each laser system may influence the thermal damage inflicted on the soft tissue, however, the wave length of each laser determines the absorption rate characteristics of every tissue and the thermal effect

PREVENTION OF CHILLING INJURY IN 'TOMMY ATKINS' MANGOES PREVIOUSLY STORED AT 5 ºC, USING HEAT TREATMENT AND RADIATION UV (UV-C)

ABSTRACT The objective of this study was to evaluate the effect of heat treatment and ultraviolet radiation (UV-C) in the prevention of chilling injury in mangoes cv. Tommy Atkins previously stored or not under injury condition after their transference to ambient condition. Fruits were divided into groups: two were hydrothermally treated (46.1 ºC/90 min; 55 ºC/5 min) and two were exposed to UV-C radiation (1.14 kJ m-2; 2.28 kJ m-2). These groups were stored under chilling injury conditions (5 ºC for 14 days), as established in preliminary tests. Other untreated groups were stored at 12 ºC or 5 ºC. After the storage period, they were transferred to ambient conditions (21.9 ºC; 55% RH) and the quality was evaluated. All the data were submitted to multivariate analysis as the tool to verify the simultaneous effect of the treatments under the quality parameters. The multivariate analysis indicated that the hydrothermal treatments at 46.1 °C/90 min and 55 °C/5 min and the UV-C radiation at doses of 1.14 kJ m-2 and 2.28 kJ m-2 were effective in minimized the symptoms of chilling injury in mangoes ‘Tommy Atkins’ stored at 5 °C for 14 days. However, after their transference to environmental condition at 21.9 °C, only the UV-C kept this control, especially at a dose of 2.28 kJ m-2. This treatment did not prevent the development of the characteristic color or affected the normal ripening and allowed the conservation of fruit for a period of 14 days at 5 °C, plus seven days of storage at environmental condition, which corresponds to the shipping transportation plus the time for sale.

An overview of the metabolic differences between Bradyrhizobium japonicum 110 bacteria and differentiated bacteroids from soybean (Glycine max) root nodules: An in vitro 13C-and 31P-nuclear magnetic resonance spectroscopy study

Bradyrhizobium japonicum is a symbiotic nitrogen-fixing soil bacteria that induce root nodules formation in legume soybean (Glycine max.). Using 13C- and 31P-nuclear magnetic resonance (NMR) spectroscopy, we have analysed the metabolite profiles of cultivated B.japonicum cells and bacteroids isolated from soybean nodules. Our results revealed some quantitative and qualitative differences between the metabolite profiles of bacteroids and their vegetative state. This includes in bacteroids a huge accumulation of soluble carbohydrates such as trehalose, glutamate, myo-inositol and homospermidine as well as Pi, nucleotide pools and intermediates of the primary carbon metabolism. Using this novel approach, these data show that most of the compounds detected in bacteroids reflect the metabolic adaptation of rhizobia to the surrounding microenvironment with its host plant cells.

Determination and characterization of quinolones in foodstuffs of animal origin by CE-UV, LC-UV, LC-Fl, LC-MS and LC-MS/MS

In this work methods for the multiresidue determination of the series of quinolones include in the European regulation in food of animal origin are de veloped and validated in line with Commission Decision 2002/657/EC in terms of linearity, decision limit, capability detection, precision and stability. Mult iresidue methods were established to allow the determination of quinolones covered by EU legislation in 2377/90/EC in muscle of chicken, turkey, pig and cow, plasma of cow and pig, liver of pig and milk of cow. First an extraction step was optimized and a SPE step was applied to clean!up and preconcentrate quinolones prior to their separation by CE or LC and determination by CE!UV, LC!UV, LC!Fl, LC!MS with different ion sources (ESI ,ApCI) and different mass analyser (Q, ToF) and LC!E SI!QqQ tandem mass spectrometry. The limits of quantification obtained are always lower than Maxim um Residue Limit (MRL) established by EU for quinolones in animal products and they can be applied to the control of quinolones in foodstuffs of animal origin . Finally the proposed methods were applied to determine quinolones in samples of turkey and pig muscle, pig plasma and milk of cow. Excellent quality parameters and reduced time of analysis were obtained when LC!ESI!MS/MS is used, although the others techniques presented too satisfactory results.

Optical spectroscopy of microquasar candidates at low Galactic latitudes

We report optical spectroscopic observations of a sample of 6 low-galactic latitude microquasar candidates selected by cross-identification of X-ray and radio point source catalogs for |b|<5 degrees. Two objects resulted to be of clear extragalactic origin, as an obvious cosmologic redshift has been measured from their emission lines. For the rest, none exhibits a clear stellar-like spectrum as would be expected for genuine Galactic microquasars. Their featureless spectra are consistent with being extragalactic in origin although two of them could be also highly reddened stars. The apparent non-confirmation of our candidates suggests that the population of persistent microquasar systems in the Galaxy is more rare than previously believed. If none of them is galactic, the upper limit to the space density of new Cygnus X-3-like microquasars within 15 kpc would be 1.1\times10^{-12} per cubic pc. A similar upper limit for new LS 5039-like systems within 4 kpc is estimated to be 5.6\times10^{-11} per cubic pc.