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1.
Br Poult Sci ; 63(6): 847-856, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35946320

RESUMO

1. The following study was conducted to evaluate the tolerability of tall oil fatty acid (TOFA) to broiler chickens, at three graded levels as a nutritional additive in complete feed.2. 256 one-day-old female and male Cobb 500 broiler chickens were assigned to four dietary treatment groups with TOFA at 0 (control), 1.0, 3.0, or 5.0 g/kg within a complete feed for 45 d.3. Birds were weighed individually on days 0, 16, 31 and 45, and the feed intake, bird weight gain, and feed conversion ratio were calculated for the respective starter, grower and finisher phases and over the whole study. On day 45, blood samples were drawn from each bird for haematology and blood chemistry measurements. Two birds per pen were subjected to gross pathological examination and sampling of several tissues for histopathology, including weighing the liver.4. The dietary treatments did not affect zootechnical performance variables or mortality over the whole study period. Bird performance was typical for the breed.5. Haematology, clinical chemistry and histopathology did not reveal any changes associated with dietary TOFA dosing. However, the 5.0 g/kg dose level increased the relative weight of the liver, as a percentage of final body weight, compared to the control group, but there was lack of corresponding histopathology findings.6. In conclusion, the study indicated that oral administration of TOFA for 45 d in feed was well tolerated by the birds at dietary levels of up to 5.0 g/kg.


Assuntos
Galinhas , Suplementos Nutricionais , Animais , Masculino , Feminino , Dieta/veterinária , Ácidos Graxos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal
2.
J Dairy Sci ; 105(2): 1211-1224, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34799103

RESUMO

We evaluated the potential of feeding high-oil rapeseed cake or natural additives as rumen modifiers on enteric methane (CH4) emissions, nutrient utilization, performance, and milk fatty acid (FA) profile of dairy cows. Eight Nordic Red dairy cows averaging (mean ± SD) 81 ± 21 d in milk and 41.0 ± 1.9 kg of milk yield at the beginning of the study were randomly assigned to a replicated 4 × 4 Latin square design with 21-d periods. Treatments comprised grass silage-based diets (45:55 forage to concentrate ratio on dry matter basis) including (1) control containing 19.3% rapeseed meal (CON), (2) CON with full replacement of rapeseed meal with rapeseed cake (RSC), (3) supplementation of CON with 50 g/d of yeast hydrolysate product plus coniferous resin acid-based compound (YHR), and (4) supplementation of CON with 20 g/d of combination of garlic-citrus extract and essential oils in a pellet (GCE). Apparent total-tract digestibility was measured using total collection of feces, and CH4 emissions were measured in respiratory chambers on 4 consecutive days. Data collected during d 17 and 21 in each period were used for ANOVA analysis using a mixed model. Treatments did not affect dry matter intake (DMI), whereas feeding RSC increased crude protein and ether extract digestibility compared with the other diets. Emissions of CH4 per day, per kilogram of DMI, and per kilogram of energy-corrected milk, and gross energy intake were lower for RSC compared with other diets. We found no effect of YHR on daily CH4 emissions, whereas CH4 yield (g of CH4/kg of DMI or as percentage of gross energy intake) decreased with GCE compared with CON. Treatments did not influence energy balance. Further, RSC reduced the proportion of N intake excreted in feces, and YHR improved N balance compared with CON diet. Feeding RSC resulted in greatest yields of milk and energy-corrected milk, and feed efficiency. Relative to the CON diet, RSC decreased saturated FA by 10% in milk fat by increasing cis-monounsaturated FA but also increased the proportion of trans FA. Proportion of odd- and branched-chain FA increased with GCE and YHR compared with CON. We conclude that replacing rapeseed meal by rapeseed cake decreased CH4 emissions, whereas YHR or GCE had no effect on CH4 emissions in this study.


Assuntos
Brassica napus , Metano , Animais , Bovinos , Dieta/veterinária , Digestão , Feminino , Lactação , Leite , Rúmen , Silagem/análise , Zea mays
3.
Ann Vasc Surg ; 66: 142-151, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31669479

RESUMO

BACKGROUND: Previous reports have indicated endovascular repair to be safe and effective in the treatment of complex aortic aneurysms. The endovascular technology evolves rapidly, and continuous evaluation of F/B-EVAR results is critical to detect failing techniques. Our aim was to analyze the outcome after endovascular repair of complex abdominal aortic and thoracoabdominal aneurysms. METHODS: Single-center, retrospective cohort study, of all F/B-EVAR from August 2009 to December 2018. Primary outcomes were branch instability and freedom from reinterventions at 2 years. Secondary outcomes were major adverse events and all-cause mortality at 30 and 90 days. RESULTS: A total of 72 consecutive patients were included, 55 with a complex abdominal aortic aneurysm (AAA) and 17 with a thoracoabdominal aortic aneurysm (TAAA). Two patients were operated on for rupture. A total of 219 vessels were stented through fenestrations (n = 163) or branches (n = 56). Median follow-up was 24 months (IQR 4-24). Fractured bridging stent graft was the most common cause for reintervention, n = 6. All fractures were in vessels stented with first generation BeGrafts, (6/41 BeGraft vs 0/61 other stents, P < 0.01). Freedom from reinterventions at 2 years was 75% and 35%, in the complex AAA and TAAA groups, respectively (P = 0.04) and excluding BeGrafts 79% (cAAA) and 66% (TAAA). The most common major adverse event was spinal cord ischemia (SCI), in total 8.3% with either transient (2.8%) or permanent (5.6%) deficit. Elective mortality at 30 days was 1.4% (1/70) and at 90 days was 2.9% (2/70). CONCLUSIONS: The rate of branch instability and reintervention was high, with a clear relation to fractured first-generation BeGrafts. Mortality and major adverse event rates were low. Long-term close surveillance of bridging stent graft performance is crucial, and the endovascular community should strive to find ways to report failing materials at an early stage to avoid potentially serious complications.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares/instrumentação , Falha de Prótese , Stents , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/mortalidade , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/mortalidade , Feminino , Humanos , Masculino , Desenho de Prótese , Reoperação , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
4.
Artigo em Inglês | MEDLINE | ID: mdl-23844575

RESUMO

The sequestration/inactivation of the oestrogenic mycotoxin zearalenone (ZEA) by two adsorbents--yeast cell wall extract (YCW) and hydrated sodium calcium aluminosilicate (HSCAS)--was studied in three laboratory models: (1) an in vitro model was adapted from referenced methods to test for the sequestrant sorption capabilities under buffer conditions at two pH values using liquid chromatography coupled to a fluorescence detector for toxin quantification; (2) a second in vitro model was used to evaluate the sequestrant sorption stability according to pH variations and using ³H-labelled ZEA at low toxin concentration; and (3) an original, ex vivo Ussing chamber model was developed to further understand the transfer of ZEA through intestinal tissue and the impact of each sequestrant on the mycotoxin bioavailability of ³H-labelled ZEA. YCW was a more efficient ZEA adsorbent than HSCAS in all three models, except under very acidic conditions (pH 2.5 or 3.0). The Ussing chamber model offered a novel, ex vivo, alternative method for understanding the effect of sequestrant on the bioavailability of ZEA. The results showed that compared with HSCAS, YCW was more efficient in sequestering ZEA and that it reduced the accumulation of ZEA in the intestinal tissue by 40% (p < 0.001).


Assuntos
Ração Animal , Produtos Biológicos/metabolismo , Parede Celular/química , Estrogênios não Esteroides/antagonistas & inibidores , Saccharomyces cerevisiae/química , Sequestrantes/metabolismo , Zearalenona/antagonistas & inibidores , Silicatos de Alumínio/química , Silicatos de Alumínio/metabolismo , Animais , Produtos Biológicos/química , Precipitação Química , Estrogênios não Esteroides/química , Estrogênios não Esteroides/metabolismo , Aditivos Alimentares/química , Aditivos Alimentares/metabolismo , Fármacos Gastrointestinais/química , Fármacos Gastrointestinais/metabolismo , Concentração de Íons de Hidrogênio , Íleo/metabolismo , Técnicas In Vitro , Absorção Intestinal , Mucosa Intestinal/metabolismo , Masculino , Ratos , Ratos Wistar , Sequestrantes/química , Solubilidade , Zearalenona/química , Zearalenona/metabolismo
5.
Appl Radiat Isot ; 71(1): 34-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23085548

RESUMO

Pure samples of (131m)Xe, (133m)Xe, (133)Xe and (135)Xe facilitate the calibration and testing of noble gas sampler stations and related laboratory instrumentation. We have earlier reported a Penning trap-based production method for pure (133m)Xe and (133)Xe samples. Here we complete the work by reporting the successful production of pure (131m)Xe and (135)Xe samples using the same technique. In addition, we present data on xenon release from graphite.

6.
Phys Med Biol ; 56(8): 2367-74, 2011 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-21427483

RESUMO

The proton stopping power of liquid water was, for the first time, measured in the energy range 4.7-15.2 MeV. The proton energies were determined by the time-of-flight transmission technique with the microchannel plate detectors, which were especially developed for timing applications. The results are compared to the literature values (from ICRU Report 49 (1993) and Janni's tabulation (1982 At. Data Nucl. Data Tables 27 147-339)) which are based on Bethe's formula and an agreement is found within the experimental uncertainty of 4.6%. Thus, earlier reported discrepancy between the experimental and literature stopping power values at lower energies was not observed at the energies considered in this experiment.


Assuntos
Prótons , Radiometria/métodos , Água/química , Simulação por Computador , Transferência Linear de Energia , Solventes/química , Fatores de Tempo
7.
Br Poult Sci ; 51(3): 381-92, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20680873

RESUMO

1. In this study the effect of a blend of essential oils (EO) comprising 15 g/tonne thymol and 5 g/tonne cinnamaldehyde on the performance and intestinal microbiota of broilers was investigated. 2. A total of 720 male Ross broilers were divided into two dietary treatments with 12 replicate pens per treatment. Broilers were given a control soybean-wheat-based diet with or without added EO in two diet phases (0-21 d and 22-42 d). 3. The blend of EO increased body weight gain of broilers from 0 to 42 d by 45%. 4. Caecal microbiota were affected by the EO blend; in particular increases in the proportions of Lactobacillus and Escherichia coli at 41 d was observed. 5. The EO blend had major effects on caecal metabolites. The proportion of caecal butyrate at 20 and 41 d of age increased, whereas the proportion of caecal acetic acid at 20 d, and propionic acid and isovaleric acid at 41 d, decreased with the EO blend. In addition, the caecal proportion of spermine increased and tyramine decreased at 41 d of age with the EO treatment. 6. The present study shows that EO supplementation exerts a positive effect on intestinal microbiota with a concomitant enhancement in growth performance. The study suggests that modulation of broiler gut microbiota composition and activity through the administration of EO offers an effective means for improving broiler performance.


Assuntos
Ração Animal , Galinhas/crescimento & desenvolvimento , Intestinos/microbiologia , Óleos Voláteis/farmacologia , Animais , Aminas Biogênicas/metabolismo , Galinhas/microbiologia , Dieta/veterinária , Ácidos Graxos/metabolismo , Masculino , Aumento de Peso/efeitos dos fármacos
8.
Appl Radiat Isot ; 68(3): 450-3, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20044263

RESUMO

A Penning trap-based purification process having a resolution of about 1 ppm is reported. In this context, we present for the first time a production method for the most complicated and crucially important nuclear weapons test signature, (133m)Xe. These pure xenon samples are required by the Comprehensive Nuclear-Test-Ban Treaty Organization to standardize and calibrate the worldwide network of xenon detectors.

9.
Phys Rev Lett ; 98(13): 132503, 2007 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-17501196

RESUMO

A rotational band has been unambiguously observed in an odd-proton transfermium nucleus for the first time. An in-beam gamma-ray spectroscopic study of 101/251Md has been performed using the gamma-ray array JUROGAM combined with the gas-filled separator RITU and the focal plane device GREAT. The experimental results, compared to Hartree-Fock-Bogolyubov calculations, lead to the interpretation that the rotational band is built on the [521]1/2(-) Nilsson state.

10.
Poult Sci ; 86(4): 643-53, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17369534

RESUMO

This research aimed to evaluate the effects of adding a combination of exogenous enzymes to starter diets varying in protein content and fed to broilers vaccinated at day of hatch with live oocysts and then challenged with mixed Eimeria spp. Five hundred four 1-d-old male Cobb-500 chickens were distributed in 72 cages. The design consisted of 12 treatments. Three anticoccidial control programs [ionophore (IO), coccidian vaccine (COV), and coccidia-vaccine + enzymes (COV + EC)] were evaluated under 3 CP levels (19, 21, and 23%), and 3 unmedicated-uninfected (UU) negative controls were included for each one of the protein levels. All chickens except those in unmedicated-uninfected negative controls were infected at 17 d of age with a mixed oral inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Live performance, lesion scores, oocyst counts, and samples for gut microflora profiles were evaluated 7 d postinfection. Ileal digestibility of amino acids (IDAA) was determined 8 d postinfection. Microbial communities (MC) were analyzed by G + C%, microbial numbers were counted by flow cytometry, and IgA concentrations were measured by ELISA. The lowest CP diets had poorer (P < or = 0.001) BW gain and feed conversion ratio in the preinfection period. Coccidia-vaccinated broilers had lower performance than the ones fed ionophore diets during pre- and postchallenge periods. Intestinal lesion scores were affected (P < or = 0.05) by anticoccidial control programs, but responses changed according to gut section. Feed additives or vaccination had no effect (P > or = 0.05) on IDAA, and diets with 23% CP had the lowest (P < or = 0.001) IDAA. Coccidial infection had no effect on MC numbers in the ileum but reduced MC numbers in ceca and suppressed ileal IgA production. The COV + EC treatment modulated MC during mixed coccidiosis infection but did not significantly improve chicken performance. Results indicated that feed enzymes may be used to modulate the gut microflora of cocci-vaccinated broiler chickens.


Assuntos
Ração Animal , Galinhas/imunologia , Galinhas/microbiologia , Coccídios/imunologia , Coccidioidomicose/veterinária , Eimeria/imunologia , Aditivos Alimentares , Doenças das Aves Domésticas/imunologia , Vacinas Protozoárias , Animais , Coccidioidomicose/imunologia , Proteínas de Plantas , Glycine max , Zea mays
11.
Phys Rev Lett ; 97(6): 062501, 2006 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-17026165

RESUMO

Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |beta2|=0.29(5) and |beta2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.

12.
Phys Rev Lett ; 95(3): 032501, 2005 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16090736

RESUMO

In-beam gamma-ray spectroscopic measurements have been made on 253/102No. A single rotational band was identified up to a probable spin of 39/2planck, which is assigned to the 7/2(+)[624] Nilsson configuration. The bandhead energy and the moment of inertia provide discriminating tests of contemporary models of the heaviest nuclei. Novel methods were required to interpret the sparse data set associated with cross sections of around 50 nb. These methods included comparisons of experimental and simulated spectra, as well as testing for evidence of a rotational band in the gammagamma matrix.

13.
Phys Rev Lett ; 89(20): 202501, 2002 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-12443472

RESUMO

The spectrum of prompt conversion electrons emitted by excited 254No nuclei has been measured, revealing discrete lines arising from transitions within the ground state band. A striking feature is a broad distribution that peaks near 100 keV and comprises high multiplicity electron cascades, probably originating from M1 transitions within rotational bands built on high K states.

14.
Artigo em Inglês | MEDLINE | ID: mdl-11691612

RESUMO

The aim of this experiment was to study the patterns of betaine accumulation into intestinal tissue, liver and plasma of broiler chicks with or without coccidial infection. The chicks were raised on a corn-based, low-betaine diet with or without 1000 ppm betaine supplementation and with or without intestinal microparasite (Eimeria maxima) challenge to the age of 21 days. Plasma, liver, intestinal tissue and digesta of non-challenged (NC) birds and plasma and intestinal tissue of coccidiosis challenged (CC) birds were analysed for betaine content. NC birds were also analyzed for homocysteine in plasma and S-adenosylmethionine (S-AM) in liver. The jejunal epithelium was histologically examined for the presence of coccidia and the crypt-villus ratio was measured. Dietary betaine supplementation decreased the plasma homocysteine concentration but had no effect on liver S-AM of NC birds. The data suggest that chicks on a low-betaine diet accumulate betaine into the intestinal tissue. When the diet was supplemented with betaine, betaine accumulated heavily into liver and to a lesser degree into intestinal tissue. The concentration of betaine in jejunal and ileal digesta was low suggesting that dietary betaine was mainly absorbed from the proximal small intestine. The coccidial challenge decreased the concentration of betaine in the liver, but greatly increased that in the intestinal tissue. The crypt-villus ratio was decreased by the dietary betaine supplementation in healthy and challenged chicks, suggesting that dietary betaine both protects the jejunal villi against coccidial infection and also stabilizes the mucosal structure in healthy broiler chicks. These results support our earlier findings suggesting that betaine is likely to act as an important intestinal osmolyte in broiler chicks.


Assuntos
Betaína/farmacocinética , Coccídios/metabolismo , Epitélio/metabolismo , Fármacos Gastrointestinais/farmacocinética , Intestinos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Animais , Galinhas , Cromatografia Líquida de Alta Pressão , Coccidiose/sangue , Coccidiose/metabolismo , Epitélio/parasitologia , Feminino , Homocisteína/sangue , Homocisteína/metabolismo , Intestinos/parasitologia , Jejuno/metabolismo , Fígado/parasitologia , Masculino , Modelos Biológicos , S-Adenosilmetionina/metabolismo
15.
Phys Rev Lett ; 87(7): 072501, 2001 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-11497885

RESUMO

Excited states in (216)Th were investigated via prompt and delayed gamma decays and the recoil-decay tagging method. The decay schemes of the I(pi) = (8+), t(1/2) = 128(8) micros, the I(pi) = (11-), t(1/2) = 615(55) ns, and the I(pi) = (14+), t(1/2) > or = 130 ns isomers were established. The configuration pi h(9/2)f(7/2) is assigned to the I(pi) = (8+) isomer, which implies that the h(9/2) and f(7/2) states are nearly degenerate. This is ascribed to increased binding of the f(7/2) orbital by its coupling to a low-lying I(pi) = (3-) state at E(x) = 1687 keV. The role of octupole and pairing correlations for a Z = 92 shell closure prediction is discussed on the basis of shell model calculations.

16.
Comp Biochem Physiol A Mol Integr Physiol ; 129(2-3): 595-603, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11423329

RESUMO

In Experiment 1, the water holding capacity of broiler chick intestinal tissue was studied in vitro. The chicks were fed with corn-based diets with or without a 0.2% betaine supplementation in the drinking water. Slices from duodenum and jejunum were incubated in iso-osmotic (300 mM) or hyperosmotic saline (600 mM) with or without 10 mM betaine. The water volume of tissue slices was studied by adding tritiated water in the incubation medium while [14C]inulin was used to correct for the adherent water. After 30 min of incubation, by which time the steady-state of tritium influx had been achieved, the 3H and 14C-activities of the tissue slices were measured. The ileal and duodenal tissues incubated in the hyperosmotic saline accumulated less tritium than those incubated in iso-osmotic saline. Duodenal slices incubated in hyperosmotic saline with the presence of betaine showed a tritium content similar to slices incubated in iso-osmotic saline. The data suggest that the presence of betaine helped the duodenal, but not jejunal, epithelium to maintain water balance in hyperosmotic conditions. The dietary betaine supplementation diminished the differences between the incubation treatments in duodenal, but not in ileal tissue. In Experiment 2, the same double labeling method, but with shorter incubation times, was used to assess the rate of water flux from the incubation medium to duodenal or jejunal slices. The dietary treatments (as in Experiment 1) had little effect on the results. Betaine in the hyperosmotic saline significantly decreased the rate of tritium accumulation into the tissue slices, indicating that betaine slowed down the influx of water to the epithelium. We suggest that betaine affects the movement of water across the intestinal epithelium and has a role in the osmoregulation of small intestine of broiler chicks.


Assuntos
Betaína/farmacologia , Galinhas , Duodeno/fisiologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Animais , Duodeno/efeitos dos fármacos , Epitélio/efeitos dos fármacos , Epitélio/fisiologia , Feminino , Íleo/efeitos dos fármacos , Íleo/fisiologia , Intestinos/efeitos dos fármacos , Intestinos/fisiologia , Jejuno/efeitos dos fármacos , Jejuno/fisiologia , Masculino , Água
17.
J Agric Food Chem ; 49(2): 559-63, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11261992

RESUMO

Betaine was measured from liver tissue by a high-performance liquid chromatographic (HPLC) method developed for this study. The method involves homogenization of liver in acetate buffer at pH 6 and precipitation of protein with trichloroacetic acid, which was removed by diethyl ether extraction. Betaine was separated using a cation exchange column in Ca(2+) form and detected with a refractive index detector. This method also allows the determination of S-adenosylmethionine (S-AM) from the same liver extract but with different HPLC conditions. Broiler chicks were fed with experimental diets supplemented with four different doses of betaine or choline ranging from 0 to 5 mol equiv. After a 3 week feeding period, the livers were analyzed for betaine and S-AM. Dietary betaine was twice as efficient in increasing the hepatic betaine concentration as dietary choline. The hepatic S-AM concentrations were similar in all dietary treatments.


Assuntos
Ração Animal , Betaína/análise , Betaína/metabolismo , Colina/metabolismo , Fígado/química , Carne/análise , Animais , Betaína/administração & dosagem , Galinhas , Colina/administração & dosagem , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Suplementos Nutricionais , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Artigo em Inglês | MEDLINE | ID: mdl-11223388

RESUMO

The efficiency of betaine absorption into small intestinal slices of broiler chicks was studied in vitro with 14C-labeled betaine. The relative proportion of Na+-coupled betaine uptake, as well as the total uptake capacity was larger in the duodenum than in the jejunum. Dietary betaine increased the Na+-coupled uptake in the duodenum. In in vivo-experiments, methyl-14C-labeled betaine, methionine, or choline was fed to broiler chicks. Betaine appeared in the blood more rapidly, and reached a higher total concentration than choline or methionine. The data suggest that choline and methionine were associated with plasma lipoproteins whereas betaine remained free in the plasma. The label distribution in liver, kidney, and intestinal tissues was studied 24 h after label ingestion. Most of the label from betaine was found in the aquaeous phase in the muscle, while in the liver and jejunum the label from betaine was distributed more evenly between the aquaeous, lipid, and protein phases. Label from choline accumulated in the lipid fraction, particularly so in the liver, whereas label from methionine showed a more variable distribution pattern. The distribution results are interpreted in terms of specific roles of betaine, choline, and methionine in methyl group metabolism.


Assuntos
Betaína/metabolismo , Colina/metabolismo , Absorção Intestinal , Metionina/metabolismo , Animais , Galinhas , Duodeno/metabolismo , Técnicas In Vitro , Jejuno/metabolismo
19.
Nature ; 405(6785): 430-3, 2000 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-10839532

RESUMO

Understanding the fundamental excitations of many-fermion systems is of significant current interest. In atomic nuclei with even numbers of neutrons and protons, the low-lying excitation spectrum is generally formed by nucleon pair breaking and nuclear vibrations or rotations. However, for certain numbers of protons and neutrons, a subtle rearrangement of only a few nucleons among the orbitals at the Fermi surface can result in a different elementary mode: a macroscopic shape change. The first experimental evidence for this phenomenon came from the observation of shape coexistence in 16O (ref. 4). Other unexpected examples came with the discovery of fission isomers and super-deformed nuclei. Here we find experimentally that the lowest three states in the energy spectrum of the neutron deficient nucleus 186Pb are spherical, oblate and prolate. The states are populated by the alpha-decay of a parent nucleus; to identify them, we combine knowledge of the particular features of this decay with sensitive measurement techniques (a highly efficient velocity filters with strong background reduction, and an extremely selective recoil-alpha-electron coincidence tagging methods). The existence of this apparently unique shape triplet is permitted only by the specific conditions that are met around this particular nucleus.

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