1000 resultados para Frediani, Julieta C.


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A protein exhibiting immunological cross-reactivity with the chicken egg-white riboflavin carrier protein was detected by radioimmunoassay in the eggs and serum of the fresh water fish Cyprinus carpio and subsequently purified to homogeneity by use of affinity chromatography. Fish riboflavin carrier protein resembled chicken riboflavin carrier protein with respect to most of its physicochemical characteristics. The major epitopes of chicken riboflavin carrier protein were shown to be conserved in the fish protein as probed with monoclonal antibodies to the avian vitamin carrier.

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AIMS An independent, powerful coronary heart disease (CHD) predictor is a low level of high-density lipoprotein cholesterol (HDL-C). Discoidal preβ-HDL particles and large HDL2 particles are the primary cholesterol acceptors in reverse cholesterol transport, a key anti-atherogenic HDL mechanism. The quality of HDL subspecies may provide better markers of HDL functionality than does HDL-C alone. We aimed I) to study whether alterations in the HDL subspecies profile exist in low-HDL-C subjects II) to explore the relationship of any changes in HDL subspecies profile in relation to atherosclerosis and metabolic syndrome; III) to elucidate the impact of genetics and acquired obesity on HDL subspecies distribution. SUBJECTS The study consisted of 3 cohorts: A) Finnish families with low HDL-C and premature CHD (Study I: 67 subjects with familial low HDL-C and 64 controls; Study II: 83 subjects with familial low HDL-C, 65 family members with normal HDL-C, and 133 controls); B) a cohort of 113 low- and 133 high-HDL-C subjects from the Health 2000 Health Examination Survey carried out in Finland (Study III); and C) a Finnish cohort of healthy young adult twins (52 monozygotic and 89 dizygotic pairs) (Study IV). RESULTS AND CONCLUSIONS The subjects with familial low HDL-C had a lower preβ-HDL concentration than did controls, and the low-HDL-C subjects displayed a dramatic reduction (50-70%) in the proportion of large HDL2b particles. The subjects with familial low HDL-C had increased carotid atherosclerosis measured as intima-media-thickness (IMT), and HDL2b particles correlated negatively with IMT. The reduction in both key cholesterol acceptors, preβ-HDL and HDL2 particles, supports the concept of impaired reverse cholesterol transport contributing to the higher CHD risk in low-HDL-C subjects. The family members with normal HDL-C and the young adult twins with acquired obesity showed a reduction in large HDL2 particles and an increase in small HDL3 particles, which may be the first changes leading to the lowering of HDL-C. The low-HDL-C subjects had a higher serum apolipoprotein E (apoE) concentration, which correlated positively with the metabolic syndrome components (waist circumference, TG, and glucose), highlighting the need for a better understanding of apoE metabolism in human atherosclerosis. In the twin study, the increase in small HDL3b particles was associated with obesity independent of genetic effects. The heritability estimate, of 73% for HDL-C and 46 to 63% for HDL subspecies, however, demonstrated a strong genetic influence. These results suggest that the relationship between obesity and lipoproteins depends on different elements in each subject. Finally, instead of merely elevating HDL-C, large HDL2 particles and discoidal preβ-HDL particles may provide beneficial targets for HDL-targeted therapy.

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The simple two dimensional C-13-satellite J/D-resolved experiments have been proposed for the visualization of enantiomers, extraction of homo- and hetero-nuclear residual dipolar couplings and also H-1 chemical shift differences between the enantiomers in the anisotropic medium. The significant advantages of the techniques are in the determination of scalar couplings of bigger organic molecules. The scalar couplings specific to a second abundant spin such as F-19 can be selectively extracted from the severely overlapped spectrum. The methodologies are demonstrated on a chiral molecule aligned in the chiral liquid crystal medium and two different organic molecules in the isotropic solutions. (C) 2010 Elsevier B.V. All rights reserved.

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Carbon-supported Pt-TiO2 (Pt-TiO2/C) catalyst with varying atomic ratio of Pt to Ti, namely, 1: 1, 2: 1, and 3: 1, is prepared by sol-gel method and its electrocatalytic activity toward oxygen-reduction reaction (ORR) is evaluated for the application in polymer electrolyte fuel cells (PEFCs). The optimum atomic ratio of Pt to Ti in Pt-TiO2/C and annealing temperature are established by cyclic voltammetry and fuel-cell-polarization studies. Pt-TiO2/C annealed at 750 degrees C with Pt and Ti in atomic ratio of 2: 1, namely, 750 Pt-TiO2/C (2: 1), shows enhanced electrocatalytic activity toward ORR. It is found that the incorporation of TiO2 with Pt ameliorates both electrocatalytic activity and stability of cathode in relation to pristine Pt cathode, currently being used in PEFCs. A power density of 0.75 W/cm(2) is achieved at 0.6 V for the PEFC with 750 Pt-TiO2/C (2: 1) as compared with 0.62 W/cm(2) at 0.6 V achieved with the PEFC comprising Pt/C as cathode catalyst while operating under identical conditions. Interestingly, carbon-supported Pt-TiO2 cathode exhibits only 6% loss in electrochemical surface area after 5000 potential cycles while it is as high as 25% for Pt/C. DOI: 10.1115/1.4002466]

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13 C resonances of carbonyl and methyl groups in amides are shifted down-field on interaction with alkali and alkaline earth metal salts. The magnitude of the shift depends on the ionic potential of the cation. Ions like Li+ bind to the amide carbonyl group both in neat amide solutions as well as in concentrated salt solutions in water.

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Test results of 24 reinforced concrete wall panels in two-way action (i.e., supported on all the four sides) and subjected to in-plane vertical load are presented. The load is applied at an eccentricity to represent possible accidental eccentricity that occurs in practice due to constructional imperfections. Influences of aspect ratio, thinness ratio, slendemess ratio, vertical steel, and horizontal steel on the ultimate load are studied. Two equations are proposed to predict the ultimate load carried by the panels. The first equation is empirical and is arrived at from trial and error fitting with test data. The second equation is semi-empirical and is developed from a modification of the buckling strength of thin rectangular plates. Both the equations are formulated so as to give a safe prediction of a large portion of ultimate strength test results. Also, ultimate load cracking load and lateral deflections of identical panels in two-way action (all four sides supported) and oneway action (top and bottom sides only supported) are compared.

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Evidence is presented for the strong interaction of oxygen and nitrogen with solid films of buckminsterfullerene based on core-level spectroscopic studies. Cr, Ni and Cu deposited on C60 films interact strongly giving rise to large changes in the C(Is) and C(2p) binding energies as well as the (2p) binding energies of the transition metals.

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Studies of ZrO2 films prepared by d.c. reactive magnetron sputtering are described. The effects of substrate temperature on the packing density, refractive index, extinction coefficient and crystallinity phase have been investigated in the temperature range 25–450 °C. The refractive index varied from 1.84 to 1.95 and extinction coefficient from 2 × 10−3 to 9.6 × 10−3. This was explained on the basis of an increase in packing density from 0.686 to 0.813. The change in packing density has been attributed to a decrease in the oxygen condensation at higher temperatures. Annealing results in a decrease in refractive index and increase in extinction coefficient. The films deposited at 150 °C showed a monoclinic phase which transforms to a tetragonal phase at higher substrate temperatures.

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Molecular dynamics (MD) studies have been carried out on the Hoogsteen hydrogen bonded parallel and the reverse Hoogsteen hydrogen banded antiparallel C.G*G triplexes. Earlier, the molecular mechanics studies had shown that the parallel structure was energetically more favourable than the antiparallel structure. To characterize the structural stability of the two triplexes and to investigate whether the antiparallel structure can transit to an energetically more favourable structure, due to the local fluctuations in the structure during the MD simulation, the two structures were subjected to 200ps of constant temperature vacuum MD simulations at 300K. Initially no constraints were applied to the structures and it was observed that for the antiparallel tripler, the structure showed a large root mean square deviation from the starting structure within the first 12ps and the N4-H41-O6 hydrogen bond in the WC duplex got distorted due to a high propeller twist and a moderate increase in the opening angle in the basepairs. Starting from an initial value of 30 degrees, helical twist of the average structure from this simulation had a value of 36 degrees, while the parallel structure stabilized at a twist of 33 degrees. In spite of the hydrogen bond distortions in the antiparallel tripler, it was energetically comparable to the parallel tripler. To examine the structural characteristics of an undistorted structure, another MD simulation was performed on the antiparallel tripler by constraining all the hydrogen bonds. This structure stabilized at an average twist of 33 degrees. In the course of the dynamics though the energy of the molecule - compared to the initial structure - improved, it did not become comparable to the parallel structure. Energy minimization studies performed in the presence of explicit water and counterions also showed the two structures to be equally favourable energetically Together these results indicate that the parallel C.G*G tripler with Hoogsteen hydrogen bonds also represents a stereochemically and energetically favourable structure for this class of triplexes.

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The self-complementary DNA fragment CCGGCGCCGG crystallizes in the rhombohedral space group R3 with unit cell parameters a = 54.07 angstrom and c = 44.59 angstrom. The structure has been determined by X-ray diffraction methods at 2.2 angstrom resolution and refined to an R value of 16.7%. In the crystal, the decamer forms B-DNA double helices with characteristic groove dimensions: compared with B-DNA of random sequence, the minor groove is wide and deep and the major groove is rather shallow. Local base pair geometries and stacking patterns are within the range commonly observed in B-DNA crystal structures. The duplex bears no resemblance to A-form DNA as might have been expected for a sequence with only GC base pairs. The shallow major groove permits an unusual crystal packing pattern with several direct intermolecular hydrogen bonds between phosphate oxygens and cytosine amino groups. In addition, decameric duplexes form quasi-infinite double helices in the crystal by end-to-end stacking. The groove geometries and accessibilities of this molecule as observed in the crystal may be important for the mode of binding of both proteins and drug molecules to G/C stretches in DNA.

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A small-cluster approximation has been used to calculate the activation barriers for the d.c. conductivity in ionic glasses. The main emphasis of this approach is on the importance of the hitherto ignored polarization energy contribution to the total activation energy. For the first time it has been demonstrated that the d.c. conductivity activation energy can be calculated by considering ionic migration to a neighbouring vacancy in a smali cluster of ions consisting of face-sharing anion polyhedra. The activation energies from the model calculations have been compared with the experimental values in the case of highly modified lithium thioborate glasses.

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Attempts have been made to understand the nature and significance of hydrogen bonds of the type X-H-C (X = 0, N) . These unusual interactions have been discussed recently. Crystallographic studies on 17a-ethynylandrosta- 2,4-dieno[2,3-d]dihydroxazol1-7 8-01 (donazole) provide direct evidence of such an 0-H.0-C interaction. Ab initio computations, IR spectroscopy, and database studies show that these hydrogen bonds, while uncommon, are energetically and structurally significant.

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Sika- ja siipikarjatilojen määrä Suomessa on vähentynyt koko EU-jäsenyyden ajan tuotannon keskittyessä yhä suurempiin yksiköihin. Tuotantomäärät ovat kasvaneet, mutta viljelijöiden tulotaso on alentunut, joten maatalouden ulkopuoliset ammatit houkuttelevat luopumaan eläinten pidosta tai maataloudesta kokonaan. Sika- ja siipikarjatalouden rakennemuutoksen taloudellisena kannustimena otettiin vuonna 2009 käyttöön sika- ja siipikarjatalouden rakennemuutoskorvaus, jota maksetaan kompensaationa sika- ja siipikarjataloudesta luopuville viljelijöille. Tämän työn tarkastelukohteena on rakennemuutoskorvaus C-tukialueella, jossa yksinään on lähes yhtä paljon sika- ja siipikarjatiloja kuin A- ja B-alueilla yhteensä. Tutkimuksen tavoitteena on selvittää, millaiset sika- ja siipikarjatilat sekä koko C-alueella että C-alueen eri osissa ovat hakeneet rakennemuutoskorvausta ja miten tilat ovat alueellisesti sijoittuneet. Maatalouden rakennepolitiikalla pyritään vaikuttamaan maatalouden yhteiskunnalliseen rakenteeseen. Rakennepoliittisilla toimilla pyritään vähentämään viljelijöiden ja tilojen määrää, jolloin maataloustulo jakaantuu pienemmälle viljelijämäärälle taaten heille suuremmat tulot. Maatalouden rakennemuutosta tapahtuu, kun maatalouden rakenteessa tapahtuu tietyllä aikavälillä muutos. Rakennemuutoksessa ja -kehityksessä on alueellisia eroja. Aluetaloustiede pyrkii selittämään, mistä alueelliset erot johtuvat ja miksi alueet erilaistuvat. Suomessa eri maakunnilla on eroja ja omia alueellisia ominaispiirteitään, joilla on suuri merkitys alueen työllisyyteen ja väestön sijoittumiseen alueella. Eri maakunnissa työllisyystilanne on vaihteleva, mutta joka maakunnassa on kuitenkin työvoimapulaa useissa sellaisissa ammateissa, joihin eläinten tai tilan pidon lopettavien viljelijöiden olisi mahdollista työllistyä. Sika- ja siipikarjatalouden rakennemuutoskorvaus on kansallinen kotieläintuki, jota maksetaan tilakohtaisen viitemäärän perusteella tiloille, jotka ovat juuri lopettaneet sika- ja siipikarjatuotantonsa tai aikovat sen lopettaa. Korvausta on voitu maksaa tukiehdot täyttävälle tuenhakijalle joko vuosina 2009–2010 tai vuosina 2010–2011 ja sen maksimimäärä on tilaa kohden enintään 20000 euroa vuodessa. Kahden korvausvuoden jälkeen tilan viitemäärä lakkautetaan ja sen jälkeen tilalle ei enää makseta sika- ja siipikarjatalouden tukia. Tilan on kuitenkin edelleen mahdollista jatkaa sika- ja siipikarjatuotantoaan markkinaehtoisena. Tutkimuksen aineisto on 389 tilan tiedot sisältävä Tiken raportti tukityypin 1612 (sika- ja siipikarjatalouden rakennemuutoskorvaus, pohjoinen) tukihakutiedoista vuodelta 2010. Tutkimusote oli kvantitatiivinen ja koska havaintoaineisto kattaa kaikki C-alueen korvauksenhakijat, tehtiin tutkimus kokonaistutkimuksena. Tutkimustulosten mukaan 63 % korvausta hakeneista tiloista sijoittuu C1-alueelle ja 54 % Etelä-Pohjanmaalle ja Pohjanmaalle. Kuntatasolla eniten rakennemuutoskorvaustiloja oli Närpiössä. C-alueella tuenhakijat olivat iältään 20–71-vuotiaita. Hakijoista 62 % harjoitti päätuotantosuuntanaan viljanviljelyä ja peltoalaa kaikilla hakijoilla oli hallinnassaan lähes 16000 ha. Rakennemuutoskorvausta maksettiin C-alueella yhteensä yli 2,3 miljoonaa euroa. Kun rakennemuutoskorvauksen viitemäärät kahden korvausvuoden jälkeen lakkautetaan, poistuu tuo-tannosta yli 9600 ey. Sekä C-alueella että kaikki ELY-keskukset huomioiden oli korvauksenhakijoita kaikkia ikäluokkia tarkasteltaessa eniten 50–59-vuotiaissa. Eniten hakijoita oli viitemääräluokassa 10,01–20 ey ja viljelyalaluokassa 25,01–40 ha, vähiten luokissa 40,01–50 ey ja 50,01 ey tai enemmän sekä 150,01 ha tai enemmän. Yleisin maksuluokka oli 3000,01–4500 euroa, harvinaisin 15000,01–20000 euroa. Rakennemuutoskorvauksella saavutettuja hyötyjä ja kustannuksia on toistaiseksi vaikea määritellä, koska vuoden 2011 maksatus on vielä kesken.