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1.
Nature ; 602(7898): 585-589, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35197615

RESUMO

Fast radio bursts (FRBs) are flashes of unknown physical origin1. The majority of FRBs have been seen only once, although some are known to generate multiple flashes2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission4,5. Recently, the discovery6 of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths6. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system7. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.

2.
Phys Rev Lett ; 125(6): 062501, 2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32845657

RESUMO

Precise antineutrino measurements are very sensitive to proper background characterization. We present an improved measurement of the ^{13}C(α,n)^{16}O reaction cross section which constitutes significant background for large ν[over ¯] detectors. We greatly improve the precision and accuracy by utilizing a setup that is sensitive to the neutron energies while making measurements of the excited state transitions via secondary γ-ray detection. Our results shows a 54% reduction in the background contributions from the ^{16}O(3^{-},6.13 MeV) state used in the KamLAND analysis.

3.
Phys Rev Lett ; 122(5): 052502, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30822004

RESUMO

The neutron-capture reaction plays a critical role in the synthesis of the elements in stars and is important for societal applications including nuclear power generation and stockpile-stewardship science. However, it is difficult-if not impossible-to directly measure neutron capture cross sections for the exotic, short-lived nuclei that participate in these processes. In this Letter we demonstrate a new technique which can be used to indirectly determine neutron-capture cross sections for exotic systems. This technique makes use of the (d,p) transfer reaction, which has long been used as a tool to study the structure of nuclei. Recent advances in reaction theory, together with data collected using this reaction, enable the determination of neutron-capture cross sections for short-lived nuclei. A benchmark study of the ^{95}Mo(d,p) reaction is presented, which illustrates the approach and provides guidance for future applications of the method with short-lived isotopes produced at rare isotope accelerators.

5.
Phys Rev Lett ; 117(9): 092502, 2016 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-27610848

RESUMO

The ß-delayed neutron emission of ^{83,84}Ga isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the ß decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed ß decay to ^{78}Ni core-excited states in ^{83,84}Ge favored by shell effects. We developed shell model calculations in the proton fpg_{9/2} and neutron extended fpg_{9/2}+d_{5/2} valence space using realistic interactions that were used to understand measured ß-decay lifetimes. We conclude that enhanced, concentrated ß-decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense ß-delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models.

6.
Phys Rev Lett ; 114(21): 212501, 2015 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-26066430

RESUMO

The Galactic 1.809-MeV γ-ray signature from the ß decay of ^{26g}Al is a dominant target of γ-ray astronomy, of which a significant component is understood to originate from massive stars. The ^{26g}Al(p,γ)^{27}Si reaction is a major destruction pathway for ^{26g}Al at stellar temperatures, but the reaction rate is poorly constrained due to uncertainties in the strengths of low-lying resonances in ^{27}Si. The ^{26g}Al(d,p)^{27}Al reaction has been employed in inverse kinematics to determine the spectroscopic factors, and hence resonance strengths, of proton resonances in ^{27}Si via mirror symmetry. The strength of the 127-keV resonance is found to be a factor of 4 higher than the previously adopted upper limit, and the upper limit for the 68-keV resonance has been reduced by an order of magnitude, considerably constraining the ^{26g}Al destruction rate at stellar temperatures.

7.
Qual Life Res ; 24(12): 2895-906, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26205768

RESUMO

PURPOSE: To describe the health-related quality of life (HRQoL) of an unselected population of patients with chronic lymphocytic leukaemia (CLL) including untreated patients. METHODS: HRQoL was measured by the EORTC QLQ-C30 including the CLL16 module, EQ-5D, and VAS in an observational study over multiple years. All HRQoL measurements per patient were connected and analysed using area under the curve analysis over the entire study duration. The total patient group was compared with the general population, and three groups of CLL patients were described separately, i.e. patients without any active treatment ("watch and wait"), chlorambucil treatment only, and patients with other treatment(s). RESULTS: HRQoL in the total group of CLL patients was compromised when compared with age- and gender-matched norm scores of the general population. CLL patients scored statistically worse on the VAS and utility score of the EQ-5D, all functioning scales of the EORTC QLQ-C30, and the symptoms of fatigue, dyspnoea, sleeping disturbance, appetite loss, and financial difficulties. In untreated patients, the HRQoL was slightly reduced. In all treatment stages, HRQoL was compromised considerably. Patients treated with chlorambucil only scored worse on the EORTC QLQ-C30 than patients who were treated with other treatments with regard to emotional functioning, cognitive functioning, bruises, uncomfortable stomach, and apathy. CONCLUSIONS: CLL patients differ most from the general population on role functioning, fatigue, concerns about future health, and having not enough energy. Once treatment is indicated, HRQoL becomes considerably compromised. This applies to all treatments, including chlorambucil, which is considered to be a mild treatment.


Assuntos
Nível de Saúde , Leucemia Linfocítica Crônica de Células B/psicologia , Qualidade de Vida , Adulto , Idoso , Clorambucila/efeitos adversos , Clorambucila/uso terapêutico , Dispneia/psicologia , Fadiga/psicologia , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Países Baixos , Transtornos do Sono-Vigília/psicologia , Inquéritos e Questionários
8.
Phys Rev Lett ; 112(17): 172701, 2014 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-24836240

RESUMO

Single-neutron states in (133)Sn and (209)Pb, which are analogous to single-electron states outside of closed atomic shells in alkali metals, were populated by the ((9)Be, (8)Be) one-neutron transfer reaction in inverse kinematics using particle-γ coincidence spectroscopy. In addition, the s(1/2) single-neutron hole-state candidate in (131)Sn was populated by ((9)Be, (10)Be). Doubly closed-shell (132)Sn (radioactive) and (208)Pb (stable) beams were used at sub-Coulomb barrier energies of 3 MeV per nucleon. Level energies, γ-ray transitions, absolute cross sections, spectroscopic factors, asymptotic normalization coefficients, and excited-state lifetimes are reported and compared with shell-model expectations. The results include a new transition and precise level energy for the 3p(1/2) candidate in (133)Sn, new absolute cross sections for the 1h(9/2) candidate in (133)Sn and 3s(1/2) candidate in (131)Sn, and new lifetimes for excited states in (133)Sn and (209)Pb. This is the first report on excited-state lifetimes of (133)Sn, which allow for a unique test of the nuclear shell model and (132)Sn double-shell closure.

9.
J Cancer Res Clin Oncol ; 149(13): 11705-11718, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37405475

RESUMO

PURPOSE: Adjuvant treatment with immune checkpoint inhibitors like PD1-antibodies (ICI) ± CTLA4-antibodies (cICI) or targeted therapy with BRAF/MEK inhibitors (TT) in high-risk melanoma patients demonstrate a significant improvement in disease-free survival (DFS). Due to specific side effects, the choice of treatment is very often driven by the risk for toxicity. This study addressed for the first time in a multicenter setting the attitudes and preferences of melanoma patients for adjuvant treatment with (c)ICI and TT. METHODS: In this study ("GERMELATOX-A"), 136 low-risk melanoma patients from 11 skin cancer centers were asked to rate side effect scenarios typical for each (c)ICI and TT with mild-to-moderate or severe toxicity and melanoma recurrence leading to cancer death. We asked patients about the reduction in melanoma relapse and the survival increase at 5 years they would require to tolerate defined side-effects. RESULTS: By VAS, patients on average valued melanoma relapse worse than all scenarios of side-effects during treatment with (c)ICI or TT. In case of severe side effects, patients required a 15% higher rate of DFS at 5 years for (c)ICI (80%) compared to TT (65%). For survival, patients required an increase of 5-10% for melanoma survival during (c)ICI (85%/80%) compared to TT (75%). CONCLUSION: Our study demonstrated a pronounced variation of patient preferences for toxicity and outcomes and a clear preference for TT. As adjuvant melanoma treatment with (c)ICI and TT will be increasingly implemented in earlier stages, precise knowledge of the patient perspective can be helpful for decision making.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Suíça/epidemiologia , Recidiva Local de Neoplasia/tratamento farmacológico , Melanoma/terapia , Pele , Inibidores de Proteínas Quinases/uso terapêutico , Estudos Retrospectivos
10.
Phys Rev Lett ; 108(10): 102501, 2012 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-22463404

RESUMO

We report on the first observation of dineutron emission in the decay of 16Be. A single-proton knockout reaction from a 53 MeV/u 17B beam was used to populate the ground state of 16Be. 16Be is bound with respect to the emission of one neutron and unbound to two-neutron emission. The dineutron character of the decay is evidenced by a small emission angle between the two neutrons. The two-neutron separation energy of 16Be was measured to be 1.35(10) MeV, in good agreement with shell model calculations, using standard interactions for this mass region.

11.
Phys Rev Lett ; 108(19): 192701, 2012 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-23003029

RESUMO

The best examples of halo nuclei, exotic systems with a diffuse nuclear cloud surrounding a tightly bound core, are found in the light, neutron-rich region, where the halo neutrons experience only weak binding and a weak, or no, potential barrier. Modern direct-reaction measurement techniques provide powerful probes of the structure of exotic nuclei. Despite more than four decades of these studies on the benchmark one-neutron halo nucleus 11Be, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the 10Be(d,​p) reaction has been used in inverse kinematics at four beam energies to study the structure of 11Be. The spectroscopic factors extracted using the adiabatic model were found to be consistent across the four measurements and were largely insensitive to the optical potential used. The extracted spectroscopic factor for a neutron in an nℓj=2s(1/2) state coupled to the ground state of 10Be is 0.71(5). For the first excited state at 0.32 MeV, a spectroscopic factor of 0.62(4) is found for the halo neutron in a 1p(1/2) state.

12.
Proc Natl Acad Sci U S A ; 105(51): 20350-5, 2008 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-19075224

RESUMO

Drainage of peatlands and deforestation have led to large-scale fires in equatorial Asia, affecting regional air quality and global concentrations of greenhouse gases. Here we used several sources of satellite data with biogeochemical and atmospheric modeling to better understand and constrain fire emissions from Indonesia, Malaysia, and Papua New Guinea during 2000-2006. We found that average fire emissions from this region [128 +/- 51 (1sigma) Tg carbon (C) year(-1), T = 10(12)] were comparable to fossil fuel emissions. In Borneo, carbon emissions from fires were highly variable, fluxes during the moderate 2006 El Niño more than 30 times greater than those during the 2000 La Niña (and with a 2000-2006 mean of 74 +/- 33 Tg C yr(-1)). Higher rates of forest loss and larger areas of peatland becoming vulnerable to fire in drought years caused a strong nonlinear relation between drought and fire emissions in southern Borneo. Fire emissions from Sumatra showed a positive linear trend, increasing at a rate of 8 Tg C year(-2) (approximately doubling during 2000-2006). These results highlight the importance of including deforestation in future climate agreements. They also imply that land manager responses to expected shifts in tropical precipitation may critically determine the strength of climate-carbon cycle feedbacks during the 21st century.


Assuntos
Clima , Conservação dos Recursos Naturais , Incêndios , Ásia , Monóxido de Carbono/análise , Secas , Ecossistema , Comunicações Via Satélite , Sphagnopsida
13.
Phys Rev Lett ; 104(11): 112701, 2010 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-20366470

RESUMO

Spectroscopic factors have been extracted for proton-rich 34Ar and neutron-rich 46Ar using the (p, d) neutron transfer reaction. The experimental results show little reduction of the ground state neutron spectroscopic factor of the proton-rich nucleus 34Ar compared to that of 46Ar. The results suggest that correlations, which generally reduce such spectroscopic factors, do not depend strongly on the neutron-proton asymmetry of the nucleus in this isotopic region as was reported in knockout reactions. The present results are consistent with results from systematic studies of transfer reactions but inconsistent with the trends observed in knockout reaction measurements.

14.
Parasite ; 17(1): 3-7, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20387732

RESUMO

The study of the morphology of a species of Plasmodium is difficult because these organisms have relatively few characters. The size of the schizont, for example, which is easy to assess is important at the specific level but is not always of great phylogenetic significance. Factors reflecting the parasite's metabolism provide more important evidence. Thus the position of the parasite within the host red cell (attachment to the host nucleus or its membrane, at one end or aligned with it) has been shown to be constant for a given species. Another structure of essential significance that is often ignored is a globule, usually refringent in nature, that was first decribed in Plasmodium vaoughani Novy & MacNeal, 1904 and that we consider to be characteristic of the subgenus Novyella. Species without this structure, previously classified in this sub-genus, are now included in the new sub-genus Papernaia n. sg.


Assuntos
Aves/parasitologia , Plasmodium/classificação , Migração Animal , Animais , Doenças das Aves/parasitologia , Aves/fisiologia , Malária/veterinária , Plasmodium/genética , Plasmodium/patogenicidade , Plasmodium falciparum/classificação , Plasmodium falciparum/genética
15.
J Autism Dev Disord ; 50(6): 1898-1906, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30815773

RESUMO

With the publication of DSM-5, many changes were introduced regarding how Autism Spectrum Disorder (ASD) would be diagnosed. Changes from DSM-IV-TR were controversial, with many arguing that individuals would lose their diagnosis with the new criteria. The purpose of this study was to examine differences in the application of diagnostic criteria across both recent versions in a sample of infants and toddlers. Fewer individuals met criteria according to DSM-5; however, a larger proportion of individuals met criteria for both. Additionally, individuals with higher levels of symptoms were more likely to meet criteria for both versions as compared to either alone. Overall, results suggest that there are meaningful differences in how DSM criteria may apply to individuals with an ASD.


Assuntos
Transtorno do Espectro Autista/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Testes Psicológicos/normas , Reprodutibilidade dos Testes
16.
Ann Oncol ; 20(4): 741-5, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19190075

RESUMO

BACKGROUND: Upregulation of N-cadherin promotes dysregulated cell growth, motility, invasiveness, plus maintenance of vascular stability and is associated with cancer progression in several human tumour types. N-cadherin is expressed also on tumour cells and the anti-N-cadherin cyclic pentapeptide ADH-1, tested in the present study, can exert a direct antitumour effect. PATIENTS AND METHODS: Adult patients with advanced solid malignancies expressing N-cadherin on tumour biopsies carried out in the previous 12 months received escalating i.v. doses of ADH-1 given weekly (initially for 3 of 4 weeks, then every week). Plasma pharmacokinetics (PK) was studied at cycle 1. Blood flow changes were assessed after first dosing in all patients treated in the initial regimen. RESULTS: In all, 129 patients were screened, 65 (50%) were N-cadherin positive, and 30 were enrolled. The doses ranged from 150 to 2400 mg/m(2); no maximum tolerated dose was reached. Treatment was well tolerated with asthenia as the most frequent adverse event. Two patients with ovarian cancer showed prolonged disease stabilisation while one patient with fallopian tube carcinoma achieved a mixed response. PK was linear in the range of doses tested. CONCLUSION: ADH-1 is the first anti-N-cadherin compound tested in humans. In N-cadherin-positive patients, ADH-1 showed an acceptable toxicity profile, linear PK and hints of antitumour activity in gynaecological cancers.


Assuntos
Antineoplásicos/uso terapêutico , Caderinas/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Peptídeos Cíclicos/uso terapêutico , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Caderinas/metabolismo , Humanos , Imageamento por Ressonância Magnética , Dose Máxima Tolerável , Neoplasias/metabolismo , Neoplasias/patologia , Peptídeos Cíclicos/efeitos adversos , Peptídeos Cíclicos/farmacocinética
17.
Science ; 234(4773): 187-9, 1986 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-17746478

RESUMO

An orbiting spacecraft and ground observatories have been used to obtain interferometric observations of cosmic radio sources. The Tracking and Data Relay Satellite System (TDRSS) was used as the orbiting observatory in conjunction with two 64- meter radio telescopes at ground observatories, one in Australia and one in Japan. The quasars 1730-130 (NRAO 530), 1510-089, and 1741-038 were observed at a frequency of 2.3 gigahertz, and a maximum projected baseline of 1.4 earth diameters was achieved. All quasar observations for which valid data were acquired resulted in detected fringes. Many of the techniques proposed for a dedicated very long baseline interferometry observatory in space were used successfully in this experiment.

19.
Oncol Res ; 17(7): 323-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19408577

RESUMO

Colorectal cancer (CRC) is one of the most common malignancies in the Western world. CRC is strongly associated with lifestyle factors. Susceptibility to CRC may be partly due to deficient detoxification capacity in the gastrointestinal tract. Genetic polymorphisms in detoxification enzymes result in variations in detoxification activities, which might influence the levels of carcinogens in the gastrointestinal tract, influencing the risk for CRC. To determine whether a genetic polymorphism in the detoxification enzyme UDP-glucuronosyltransferase 2B7 (UGT2B7) predisposes to CRC, 411 Caucasian patients with sporadic CRC and 600 Caucasian controls recruited from the same geographic area were genotyped for the functional UGT2B7 H268Y polymorphism. DNA was isolated and tested by a dual-color real-time polymerase chain reaction assay. Overall, no differences in genotype distributions between patients with CRC and controls were observed. When analyzed with respect to tumor location, a shift from the UGT2B7*I *2 into the UGT2B7*2*2 genotype was seen in patients with proximal CRC (OR 1.80, 95% CI 1.11-2.89). In the male patient subpopulation an even stronger association was observed (*1*1 + *1*2 vs. *2*2: OR 2.17, 95% CI 1.11-4.04; *1*2 vs. *2*2: OR 2.19, 95% CI 1.10-4.37). No associations with respect to tumor stage were seen. In conclusion, the frequency of the UGT2B7*2*2 genotype is higher in CRC patients with proximal location of the tumor, especially in males, which suggests that this genotype is associated with an increased risk for proximal CRC.


Assuntos
Neoplasias Colorretais/genética , Glucuronosiltransferase/genética , Polimorfismo Genético/genética , Estudos de Casos e Controles , Neoplasias Colorretais/patologia , DNA/genética , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Fatores de Risco
20.
Br J Surg ; 95(4): 499-505, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18161889

RESUMO

BACKGROUND: Patients with familial adenomatous polyposis (FAP) are at high risk of developing duodenal adenomas and carcinomas. Besides germline mutations in the adenomatous polyposis coli (APC) gene, additional factors may influence the age of onset and number of duodenal adenomas. This study compared the genotype distributions of duodenal detoxification enzyme isoforms in patients with FAP and controls. METHODS: The study included 85 patients with FAP and 218 healthy age- and sex-matched controls. Genotyping of all participants using polymerase chain reaction was performed to detect polymorphisms in isoforms of uridine 5'-diphosphate glucuronosyltransferases (UGTs) and glutathione S-transferases (GSTs): UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A10, UGT2B4, UGT2B7, UGT2B15, GSTA1, GSTP1, GSTM1 and GSTT1. RESULTS: The variant genotypes of UGT1A3 were less common in patients with FAP than in controls (odds ratio 0.39 (95 per cent confidence interval 0.22 to 0.67)). There were no associations between FAP and the other polymorphic genes. The polymorphisms investigated had no predictive value for the severity of duodenal adenomatosis in patients with FAP. CONCLUSION: Although the variant genotypes of UGT1A3 were less common in patients with FAP than in those without, this did not modulate the severity of duodenal adenomatosis.


Assuntos
Polipose Adenomatosa do Colo/enzimologia , Neoplasias Duodenais/enzimologia , Genes APC , Glucuronosiltransferase/genética , Glutationa Transferase/genética , Polimorfismo Genético/genética , Adulto , Feminino , Genótipo , Humanos , Masculino
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