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Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of ßâ¼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Zâ¼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.
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Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at â¼250 MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.
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Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at â¼250 MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.
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The first measurement of the low-lying states of the neutron-rich ^{110}Zr and ^{112}Mo was performed via in-beam γ-ray spectroscopy after one proton removal on hydrogen at â¼200 MeV/nucleon. The 2_{1}^{+} excitation energies were found at 185(11) keV in ^{110}Zr, and 235(7) keV in ^{112}Mo, while the R_{42}=E(4_{1}^{+})/E(2_{1}^{+}) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions. We conclude that first levels of ^{110}Zr exhibit a rotational behavior, in agreement with previous observations of lighter zirconium isotopes as well as with the most advanced Monte Carlo shell model predictions. The data, therefore, do not support a harmonic oscillator shell stabilization scenario at Z=40 and N=70. The present data also invalidate predictions for a tetrahedral ground state symmetry in ^{110}Zr.
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The ß-decay half-lives of 94 neutron-rich nuclei ^{144-151}Cs, ^{146-154}Ba, ^{148-156}La, ^{150-158}Ce, ^{153-160}Pr, ^{156-162}Nd, ^{159-163}Pm, ^{160-166}Sm, ^{161-168}Eu, ^{165-170}Gd, ^{166-172}Tb, ^{169-173}Dy, ^{172-175}Ho, and two isomeric states ^{174m}Er, ^{172m}Dy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of ß-decay half-lives are observed at neutron-number N=97 for _{58}Ce, _{59}Pr, _{60}Nd, and _{62}Sm, and N=105 for _{63}Eu, _{64}Gd, _{65}Tb, and _{66}Dy. Features in the data mirror the interplay between pairing effects and microscopic structure. r-process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.
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One-neutron knockout reactions have been performed on a beam of radioactive ^{53}Co in a high-spin isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 11^{+} band-termination state, of the proton-rich nucleus ^{52}Co (Z=27, N=25). This has in turn enabled a study of mirror energy differences in the A=52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the experimental observations.
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This Letter reports on a systematic study of ß-decay half-lives of neutron-rich nuclei around doubly magic (208)Pb. The lifetimes of the 126-neutron shell isotone (204)Pt and the neighboring (200-202)Ir, (203)Pt, (204)Au are presented together with other 19 half-lives measured during the "stopped beam" campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden ß strength reveal significant deviations for most of the nuclei with N<126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during ß decay back to stability.
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The first spectroscopy of excited states in 52Ni (T(z)=-2) and 51Co (T(z)=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement.
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BACKGROUND: The gut microbiota contributes to macrophage-mediated inflammation in adipose tissue with consumption of an obesogenic diet, thus driving the development of metabolic syndrome. There is a need to identify and develop interventions that abrogate this condition. The hops-derived prenylated flavonoid xanthohumol (XN) and its semi-synthetic derivative tetrahydroxanthohumol (TXN) attenuate high-fat diet-induced obesity, hepatosteatosis, and metabolic syndrome in C57Bl/6J mice. This coincides with a decrease in pro-inflammatory gene expression in the gut and adipose tissue, together with alterations in the gut microbiota and bile acid composition. RESULTS: In this study, we integrated and interrogated multi-omics data from different organs with fecal 16S rRNA sequences and systemic metabolic phenotypic data using a Transkingdom Network Analysis. By incorporating cell type information from single-cell RNA-seq data, we discovered TXN attenuates macrophage inflammatory processes in adipose tissue. TXN treatment also reduced levels of inflammation-inducing microbes, such as Oscillibacter valericigenes, that lead to adverse metabolic phenotypes. Furthermore, in vitro validation in macrophage cell lines and in vivo mouse supplementation showed addition of O. valericigenes supernatant induced the expression of metabolic macrophage signature genes that are downregulated by TXN in vivo. CONCLUSIONS: Our findings establish an important mechanism by which TXN mitigates adverse phenotypic outcomes of diet-induced obesity and metabolic syndrome. TXN primarily reduces the abundance of pro-inflammatory gut microbes that can otherwise promote macrophage-associated inflammation in white adipose tissue. Video Abstract.
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Microbioma Gastrointestinal , Síndrome Metabólica , Animais , Camundongos , Síndrome Metabólica/tratamento farmacológico , RNA Ribossômico 16S/genética , Tecido Adiposo , Obesidade , InflamaçãoRESUMO
The neutron-rich lead isotopes, up to (216)Pb, have been studied for the first time, exploiting the fragmentation of a primary uranium beam at the FRS-RISING setup at GSI. The observed isomeric states exhibit electromagnetic transition strengths which deviate from state-of-the-art shell-model calculations. It is shown that their complete description demands the introduction of effective three-body interactions and two-body transition operators in the conventional neutron valence space beyond (208)Pb.
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BACKGROUND: Impairments in balance performance are a commonly accepted risk factor for falling in older people. Since there is a higher reported incidence of falling in women, it is of interest to test whether this correlates with poorer balance performance in women than men at the time of retirement in order to plan health promotional strategies. The purpose of this study was to investigate whether any gender differences exist in balance performance in people approaching retirement age. METHODS: Ninety-seven healthy volunteers (44 males, 53 females) planning to retire shortly were enrolled in the study (age range 50-67 years). Balance assessments during quiet standing were performed under various conditions; feet together eyes open, feet together eyes closed and single limb stance eyes open. The range of centre of pressure displacement in both the anterior-posterior and medial-lateral planes was collected for each task using a force platform. FINDINGS: For several of the balance tasks the men exhibited a statistically significant larger range of centre of pressure displacement than the women (P<0.01). However, after normalising the data for height, no gender differences were seen. Over half of the group failed to complete all three single limb stance trials on both limbs. INTERPRETATION: When the data was normalised for height, no differences were found in static balance performance between men and women of retirement age. A number of participants demonstrated balance impairments whilst performing the single limb stance likely to affect functional activities. Health promotional messages should be targeted equally at men and women.
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Movimento/fisiologia , Exame Físico/métodos , Equilíbrio Postural/fisiologia , Postura/fisiologia , Aposentadoria , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Fatores Sexuais , Análise e Desempenho de TarefasRESUMO
PURPOSE: To determine the pattern of changes of rectum and bladder structures during conformal therapy of T3 prostate cancer and the impact of these changes on the accuracy of the dose-volume histograms (DVHs) and normal tissue complication probabilities (NTCPs) of these organs, based on the planning computed tomography (CT) scan only. METHODS AND MATERIALS: For 11 T3 prostate cancer patients treated with conformal therapy, three repeat CT scans were made in Weeks 2, 4, and 6 of the treatment. The bony anatomy was aligned with the planning CT scan, using three dimensional (3D) chamfer matching. The internal and external surfaces of rectum and bladder were contoured in each scan. Three volumes were calculated for each organ: solid organ (including filling), filling, and wall volume. DVHs and NTCPs were calculated for all structures. RESULTS: The solid organ and filling volumes varied considerably between patients and within a patient and they decreased with increasing treatment time. The largest patient variation was seen for patients with large initial filling volumes. The variations of rectum and bladder wall volumes during treatment were 9 and 17% (1 standard deviation (SD)), respectively, with no time trend. The changes of the high dose (> 80 and 90% of the prescribed dose) volumes of the rectum in response to rectum filling differences were proportional to the whole rectum volume changes. The variation of the high-dose rectum wall volume was relatively small (14%, 1 SD). As a result, the NTCPs of rectum and rectum wall were the same overall and the variation of the NTCPs during treatment was about 14% (1 SD) and not correlated with rectum filling. The variation of the high-dose bladder volumes (about 14%, 1 SD) was smaller than the variation of the whole bladder volumes (30%, 1 SD). The high-dose bladder wall volume decreased significantly due to wall distention as the bladder filling increased. As a result of this complex pattern, the variation of NTCPs of bladder (85%, 1 SD) and bladder wall (88%, 1 SD) during treatment was large and significantly correlated with bladder filling. CONCLUSIONS: The planning CT scan overestimates rectum and bladder filling during treatment. Furthermore, the variation of filling is so large that only the wall structures have relatively constant volumes during treatment. For the rectum wall, the DVHs and NTCPs, as estimated from the initial scan, are representative for the whole treatment, because no correlation was seen between these parameters and organ filling. For the bladder wall, however, such a correlation was present and consequently, the initial bladder wall DVHs and NTCPs can only be representative for the whole treatment, if the bladder filling can be kept reasonably constant during treatment.
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Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador , Reto , Bexiga Urinária , Antropometria , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Doses de Radiação , Reto/anatomia & histologia , Reto/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Bexiga Urinária/anatomia & histologia , Bexiga Urinária/diagnóstico por imagemRESUMO
PURPOSE: To investigate whether Dose-Volume Histogram (DVH) parameters can be used to identify risk groups for developing late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer. METHODS AND MATERIALS: DVH parameters were analyzed for 130 patients with localized prostate cancer, treated with conformal radiotherapy in a dose-escalating protocol (70-78 Gy, 2 Gy per fraction). The incidence of late (>6 months) GI and GU complications was classified using the RTOG/EORTC and the SOMA/LENT scoring system. In addition, GI complications were divided in nonsevere and severe (requiring one or more laser treatments or blood transfusions) rectal bleeding. The median follow-up time was 24 months. We investigated whether rectal and bladder wall volumes, irradiated to various dose levels, correlated with the observed actuarial incidences of GI and GU complications, using volume as a continuous variable. Subsequently, for each dose level in the DVH, the rectal wall volumes were dichotomized using different volumes as cutoff levels. The impact of the total radiation dose, and the maximum radiation dose in the rectal and bladder wall was analyzed as well. RESULTS: The actuarial incidence at 2 years for GI complications > or =Grade II was 14% (RTOG/EORTC) or 20% (SOMA/LENT); for GU complications > or =Grade III 8% (RTOG/EORTC) or 21% (SOMA/LENT). Neither for GI complications > or =Grade II (RTOG/EORTC or SOMA/LENT), nor for GU complications > or =Grade III (RTOG/EORTC or SOMA/LENT), was a significant correlation found between any of the DVH parameters and the actuarial incidence of complications. For severe rectal bleeding (actuarial incidence at 2 years 3%), four consecutive volume cutoff levels were found, which significantly discriminated between high and low risk. A trend was observed that a total radiation dose > or = 74 Gy (or a maximum radiation dose in the rectal wall >75 Gy) resulted in a higher incidence of severe rectal bleeding (p = 0.07). CONCLUSIONS: These data show that dose escalation up to 78 Gy, using a conformal technique, is feasible. However, these data have also demonstrated that the incidence of severe late rectal bleeding is increased above certain dose-volume thresholds.
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Neoplasias da Próstata/radioterapia , Lesões por Radiação/epidemiologia , Reto/efeitos da radiação , Bexiga Urinária/efeitos da radiação , Relação Dose-Resposta à Radiação , Seguimentos , Humanos , Incidência , Masculino , Dosagem Radioterapêutica , Radioterapia Assistida por ComputadorRESUMO
To assess the role of different factors on the long-term antihypertensive effect of regular exercise we examined the time course of changes in haemodynamics, oxygen consumption and plasma noradrenaline in 10 normal healthy subjects. For 12 weeks, subjects performed alternating months of training and detraining in a random order. Training involved 40 min of bicycle exercise three times per week at 60-70% of maximum work. Steady-state changes at the end of 1 month's exercise were: (1) falls in resting blood pressure when supine and erect by 8/5 and 10/6 mmHg, respectively (P less than 0.01); (2) a reduction in the total peripheral resistance index of 14%; (3) an increase in maximum oxygen consumption of 14% (P less than 0.005); and (4) a fall in plasma noradrenaline of 21% (P less than 0.05). A significant fall in blood pressure occurred at the third training bout (P less than 0.005), at the beginning of the second week, and no further reduction occurred beyond the fourth bout of exercise. The reduction in plasma noradrenaline concentration was confined to the second half of the month in which exercise took place and lagged behind the blood pressure changes. There were significant differences between the rates of the initial fall of blood pressure and noradrenaline, and the times taken for the maximum changes to occur (P less than 0.05). During detraining, blood pressure remained low for 1-2 weeks after cessation of exercise, as did plasma noradrenaline. Both then rose gradually towards the initial sedentary levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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Sistema Nervoso Autônomo/fisiologia , Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Hipertensão/prevenção & controle , Adulto , Feminino , Humanos , Masculino , Norepinefrina/sangue , Educação Física e Treinamento , Resistência Física/fisiologia , Fatores de Tempo , Resistência Vascular/fisiologiaRESUMO
We recorded full-field electroretinograms from a family with two daughters with microcephaly and chorioretinal degeneration and a third daughter and mother with microcephaly without chorioretinal degeneration. The two siblings with inferior chorioretinal degeneration showed electroretinographic responses to 0.5-Hz white light that were reduced 60% to 70% below normal, suggesting that the loss of photoreceptor function exceeded the areas of visible atrophy. The mother and third daughter had normal electroretinograms. The two siblings, ages 12 and 21 years, had virtually the same electroretinographic amplitudes. In a second family, a man with microcephaly and inferior chorioretinal degeneration, examined at ages 9 and 23 years, also showed 60% to 70% reduction in electroretinographic responses to 0.5-Hz white light and showed no change in amplitudes over the 14-year interval. These findings suggest that the chorioretinal degeneration sometimes associated with microcephaly is stable in young adult life, although the long-term prognosis remains to be defined.
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Doenças da Coroide/complicações , Eletrorretinografia , Microcefalia/complicações , Degeneração Retiniana/complicações , Adolescente , Adulto , Criança , Doenças da Coroide/genética , Doenças da Coroide/fisiopatologia , Feminino , Fundo de Olho , Humanos , Masculino , Microcefalia/genética , Pessoa de Meia-Idade , Células Fotorreceptoras/fisiopatologia , Degeneração Retiniana/genética , Degeneração Retiniana/fisiopatologia , Acuidade VisualRESUMO
We evaluated full-field electroretinograms from members of a family with X-linked cone degeneration. The 15-year-old propositus had near normal visual acuity and a protan deficiency. His maternal grandfather and great uncle had a visual acuity of 20/200, a deficiency in color vision, and signs of macular degeneration; all had normal rod electroretinographic responses and diminished cone electroretinographic responses. The mother and maternal aunt of the propositus had normal visual acuity and diminished cone electroretinograms with predominant loss of red cone function. Their cone responses were greater than those of affected males. Genomic DNA isolated from these patients was analyzed with a red cone pigment gene cDNA probe that disclosed a 6.5-kilobase deletion in the red cone pigment gene. These findings substantiate that a defect in a gene encoding for a cone photoreceptor protein can lead to a cone photoreceptor degeneration.
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Eletrorretinografia , Células Fotorreceptoras/patologia , Degeneração Retiniana/genética , Adolescente , Adulto , Idoso , Southern Blotting , Deleção Cromossômica , DNA/genética , Sondas de DNA , Enzimas de Restrição do DNA , Feminino , Ligação Genética , Humanos , Masculino , Linhagem , Células Fotorreceptoras/metabolismo , Células Fotorreceptoras/fisiopatologia , Degeneração Retiniana/fisiopatologia , Pigmentos da Retina/genética , Acuidade Visual , Campos Visuais , Cromossomo XRESUMO
Lifetimes of levels from K(π) = 2(+), K(π) = 4(+) and several K(π) = 0(+) bands have been measured in the (178)Hf nucleus using the GRID technique. Lifetimes of the 2(+) and 3(+) levels were measured within the K(π) = 2(+) γ band. A lower limit was established for the lifetime of the 4(+) level of the K(π) = 4(+) band. The resulting upper limits for the absolute B(E2) values exclude collective transitions from the K(π) = 4(+) to the ground state band but not to the K(π)= 2(+) band. Level lifetimes were also measured for several states within three separate K(π)= 0(+) bands. Evidence is presented for a previously unobserved case of two excited K(π)= 0(+) bands being connected via collective E2 transitions.
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We report on a gamma-ray coincidence analysis using a mixed array of hyperpure germanium and cerium-doped lanthanum tri-bromide (LaBr3:Ce) scintillation detectors to study nuclear electromagnetic transition rates in the pico-to-nanosecond time regime in 33,34P and 33S following fusion-evaporation reactions between an 18O beam and an isotopically enriched 18O implanted tantalum target. Energies from decay gamma-rays associated with the reaction residues were measured in event-by-event coincidence mode, with the measured time difference information between the pairs of gamma-rays in each event also recorded using the ultra-fast coincidence timing technique. The experiment used the good full-energy peak resolution of the LaBr3:Ce detectors coupled with their excellent timing responses in order to determine the excited state lifetime associated with the lowest lying, cross-shell, Iπ=4- "intruder" state previously reported in the N=19 isotone 34P. The extracted lifetime is consistent with a mainly single-particle M2 multipolarity associated with a f7/2âd5/2 single particle transition.