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1.
Eur Phys J A Hadron Nucl ; 59(2): 15, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36751673

RESUMO

Muonic atom spectroscopy-the measurement of the x rays emitted during the formation process of a muonic atom-has a long standing history in probing the shape and size of nuclei. In fact, almost all stable elements have been subject to muonic atom spectroscopy measurements and the absolute charge radii extracted from these measurements typically offer the highest accuracy available. However, so far only targets of at least a few hundred milligram could be used as it required to stop a muon beam directly in the target to form the muonic atom. We have developed a new method relying on repeated transfer reactions taking place inside a 100 bar hydrogen gas cell with an admixture of 0.25% deuterium that allows us to drastically reduce the amount of target material needed while still offering an adequate efficiency. Detailed simulations of the transfer reactions match the measured data, suggesting good understanding of the processes taking place inside the gas mixture. As a proof of principle we demonstrate the method with a measurement of the 2p-1s muonic x rays from a 5  µ g gold target.

2.
Phys Rev Lett ; 129(18): 182502, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36374704

RESUMO

We report the first precise measurement of a ß-recoil correlation from a radioactive noble gas (^{6}He) confined via a magneto-optical trap. The measurement is motivated by the search for exotic tensor-type contributions to the charged weak current. Interpreted as tensor currents with right-handed neutrinos, the measurements yield |C_{T}/C_{A}|^{2}≤0.022 (90% confidence limit, C.L.). On the other hand, for left-handed neutrinos the limits are 0.007

3.
Phys Rev Lett ; 125(16): 164802, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33124843

RESUMO

We demonstrate efficient transverse compression of a 12.5 MeV/c muon beam stopped in a helium gas target featuring a vertical density gradient and crossed electric and magnetic fields. The muon stop distribution extending vertically over 14 mm was reduced to a 0.25 mm size (rms) within 3.5 µs. The simulation including cross sections for low-energy µ^{+}-He elastic and charge exchange (µ^{+}↔ muonium) collisions describes the measurements well. By combining the transverse compression stage with a previously demonstrated longitudinal compression stage, we can improve the phase space density of a µ^{+} beam by a factor of 10^{10} with 10^{-3} efficiency.

4.
Phys Rev Lett ; 124(8): 081803, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32167372

RESUMO

We present the result of an experiment to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute using Ramsey's method of separated oscillating magnetic fields with ultracold neutrons. Our measurement stands in the long history of EDM experiments probing physics violating time-reversal invariance. The salient features of this experiment were the use of a ^{199}Hg comagnetometer and an array of optically pumped cesium vapor magnetometers to cancel and correct for magnetic-field changes. The statistical analysis was performed on blinded datasets by two separate groups, while the estimation of systematic effects profited from an unprecedented knowledge of the magnetic field. The measured value of the neutron EDM is d_{n}=(0.0±1.1_{stat}±0.2_{sys})×10^{-26} e.cm.

5.
Neurocase ; 22(2): 135-44, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26237526

RESUMO

Physical activity (PA) and cardiorespiratory fitness (CRF) are associated with successful brain and cognitive aging. However, little is known about the effects of PA, CRF, and exercise on the brain in the oldest-old. Here we examined white matter (WM) integrity, measured as fractional anisotropy (FA) and WM hyperintensity (WMH) burden, and hippocampal (HIPP) volume of Olga Kotelko (1919-2014). Olga began training for competitions at age of 77 and as of June 2014 held over 30 world records in her age category in track-and-field. We found that Olga's WMH burden was larger and the HIPP was smaller than in the reference sample (58 healthy low-active women 60-78 years old), and her FA was consistently lower in the regions overlapping with WMH. Olga's FA in many normal-appearing WM regions, however, did not differ or was greater than in the reference sample. In particular, FA in her genu corpus callosum was higher than any FA value observed in the reference sample. We speculate that her relatively high FA may be related to both successful aging and the beneficial effects of exercise in old age. In addition, Olga had lower scores on memory, reasoning and speed tasks than the younger reference sample, but outperformed typical adults of age 90-95 on speed and memory. Together, our findings open the possibility of old-age benefits of increasing PA on WM microstructure and cognition despite age-related increase in WMH burden and HIPP shrinkage, and add to the still scarce neuroimaging data of the healthy oldest-old (>90 years) adults.


Assuntos
Atletas/psicologia , Cognição/fisiologia , Hipocampo/anatomia & histologia , Substância Branca/anatomia & histologia , Acelerometria , Idoso , Idoso de 80 Anos ou mais , Anisotropia , Atletas/história , Imagem de Tensor de Difusão , Pessoas Famosas , Feminino , História do Século XX , História do Século XXI , Humanos , Pessoa de Meia-Idade , Testes Neuropsicológicos
6.
Eur J Clin Microbiol Infect Dis ; 33(8): 1267-71, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24569948

RESUMO

Non-tuberculous mycobacteria are a rare but serious cause of peritoneal dialysis-related peritonitis. There are no clear guidelines for treating non-tuberculous mycobacteria peritoneal dialysis-associated infections. It has been recommended that at least two antibiotics be given for a prolonged period and peritoneal catheter should be removed. This paper describes the clinical course and treatment of a patient with M. chelonae peritoneal dialysis-related peritonitis and reviews the previously published cases.


Assuntos
Infecções por Mycobacterium não Tuberculosas/diagnóstico , Mycobacterium chelonae , Peritonite/diagnóstico , Antibacterianos/uso terapêutico , Claritromicina/uso terapêutico , Humanos , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Diálise Peritoneal , Peritonite/tratamento farmacológico , Peritonite/microbiologia
7.
Phys Rev Lett ; 108(12): 122502, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22540577

RESUMO

Studies of 6He beta decay along with tritium can play an important role in testing ab initio nuclear wave-function calculations and may allow for fixing low-energy constants in effective-field theories. Here, we present an improved determination of the 6He half-life to a relative precision of 3×10(-4). Our value of 806.89±0.11(stat)(-0.19syst)(+0.23) ms resolves a major discrepancy between previous measurements. Calculating the statistical rate function we determined the ft value to be 803.04(-0.23)(+0.26) s. The extracted Gamow-Teller matrix element agrees within a few percent with ab initio calculations.

8.
Phys Rev Lett ; 107(14): 141301, 2011 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-22107183

RESUMO

Fifteen months of cumulative CoGeNT data are examined for indications of an annual modulation, a predicted signature of weakly interacting massive particle (WIMP) interactions. Presently available data support the presence of a modulated component of unknown origin, with parameters prima facie compatible with a galactic halo composed of light-mass WIMPs. Unoptimized estimators yield a statistical significance for a modulation of ∼2.8σ, limited by the short exposure.

9.
Science ; 262(5134): 713-8, 1993 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-8235591

RESUMO

The Spermann organizer induces neural tissue from dorsal ectoderm and dorsalizes lateral and ventral mesoderm in Xenopus. The secreted factor noggin, which is expressed in the organizer, can mimic the dorsalizing signal of the organizer. Data are presented showing that noggin directly induces neural tissue, that it induces neural tissue in the absence of dorsal mesoderm, and that it acts at the appropriate stage to be an endogenous neural inducing signal. Noggin induces cement glands and anterior brain markers, but not hindbrain or spinal cord markers. Thus, noggin has the expression pattern and activity expected of an endogenous neural inducer.


Assuntos
Indução Embrionária/fisiologia , Sistema Nervoso/embriologia , Proteínas/fisiologia , Animais , Blastocisto/metabolismo , Células CHO , Proteínas de Transporte , Cricetinae , Gástrula/metabolismo , Humanos , Mesoderma/metabolismo , RNA Mensageiro/metabolismo , Proteínas Recombinantes , Xenopus
10.
Clin Nephrol ; 71(1): 43-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19203549

RESUMO

BACKGROUND: Hemodialysis arteriovenous graft (AVG) patency is dependent on favorable flow characteristics. We examined hemodynamic, humoral risk factors, and the effects of stringent flow surveillance coupled with prompt corrective intervention on long-term graft patency. METHODS: Over a 29-month period 92 chronic hemodialysis patients with AVG were evaluated monthly by flow surveillance. Clinical diagnosis of failing graft, which promoted angiography and corrective intervention was based on flow reduction, and patient's unique medical history and hemodynamic parameters. RESULTS: Graft arteriography revealed stenotic lesions in 94.5% of the cases, necessitating endovascular or surgical angioplasty. Low ejection fraction, early postoperative intervention, and low baseline flow were associated with a statistically significant reduction in intervention-free interval (p < 0.05). Mean AVG flow threshold prior to intervention was 463 +/- 154 ml/min, corresponding to a mean flow reduction of 45 +/- 12%. Total graft thrombosis rate was 0.21 thrombotic episodes/patient year. Primary graft patency at 6, 12, and 24 months was 76, 44 and 35%, and secondary patency 99, 97, 88%, respectively. CONCLUSIONS: Stringent flow surveillance policy coupled with prompt intervention has been proven effective in maintaining AVG long-term patency. Patients with decreased ejection fraction, early post-operative intervention, and low baseline AVG flow are prone to graft thrombosis.


Assuntos
Derivação Arteriovenosa Cirúrgica , Oclusão de Enxerto Vascular/diagnóstico , Oclusão de Enxerto Vascular/terapia , Falência Renal Crônica/terapia , Fluxo Sanguíneo Regional/fisiologia , Diálise Renal , Idoso , Cateteres de Demora , Estudos de Coortes , Feminino , Oclusão de Enxerto Vascular/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Trombose/diagnóstico , Trombose/etiologia , Trombose/terapia , Grau de Desobstrução Vascular/fisiologia
11.
Eur J Med Res ; 13(1): 39-46, 2008 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-18226996

RESUMO

BACKGROUND: Aim of our study was to evaluate the clinical and radiographic outcome of the first 300 consecutively implanted Birmingham Hip Resurfacing arthroplasties (BHR) in our department. METHODS: 300 BHR arthroplasties were performed in 263 patients until May 2003. Primary clinical endpoints of the investigation were the implant survival and the total Harris hip score, assessed at the last examination. RESULTS: At a median follow-up time of 24 months the Kaplan/Meier survivor estimate was 98%. 6 implant revisions were performed due to infection (2), malposition (1), femoral neck fracture (1), primary unstable cup (1) and chronic pain (1), respectively. The median Harris hip score improved from 51 points to 96 points at last follow-up. No hip showed radiographic signs of aseptic implant loosening. CONCLUSIONS: The preliminary experience with the BHR for the younger adult requiring hip arthroplasty is encouraging, but has to be reproduced in the long-term.


Assuntos
Artroplastia de Quadril/métodos , Articulação do Quadril/diagnóstico por imagem , Prótese de Quadril , Adolescente , Adulto , Idoso , Artroplastia de Quadril/efeitos adversos , Doenças Ósseas/etiologia , Doenças Ósseas/cirurgia , Feminino , Seguimentos , Articulação do Quadril/fisiopatologia , Articulação do Quadril/cirurgia , Humanos , Artropatias/etiologia , Artropatias/cirurgia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Falha de Prótese , Radiografia , Reoperação , Resultado do Tratamento
12.
Arch Intern Med ; 144(1): 95-6, 1984 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6140907

RESUMO

Three patients with Takayasu's disease (TD), initially observed with hypertension and/or congestive heart failure, were treated with captopril, an orally active inhibitor of converting enzyme. As arteritis in this disease is diffuse and extensive, surgical correction of renovascular hypertension is often delayed or impossible. Our experience enables us to recommend captopril for conservative treatment in TD.


Assuntos
Síndromes do Arco Aórtico/tratamento farmacológico , Captopril/uso terapêutico , Prolina/análogos & derivados , Arterite de Takayasu/tratamento farmacológico , Adulto , Angiografia , Criança , Feminino , Insuficiência Cardíaca/complicações , Humanos , Hipertensão Renovascular/complicações , Masculino , Obstrução da Artéria Renal/diagnóstico por imagem , Arterite de Takayasu/complicações
13.
Chest ; 93(6): 1306-7, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3371111

RESUMO

A case of localized intrathoracic Castleman tumor demonstrated, on CT scan, calcifications in a circumferential distribution. The prevalence of calcifications in Castleman's disease and the differential diagnosis of the above unusual CT findings are discussed.


Assuntos
Hiperplasia do Linfonodo Gigante/diagnóstico por imagem , Adulto , Calcinose/diagnóstico por imagem , Hiperplasia do Linfonodo Gigante/patologia , Humanos , Masculino , Tomografia Computadorizada por Raios X
14.
J Hum Hypertens ; 4(4): 425-30, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2258889

RESUMO

Blood pressure (BP) and anthropometric data were collected on 483 recent immigrants from Ethiopia to Israel, and on 171 adults and 100 adolescent boarding school students who had immigrated two to three years earlier. Comparison of samples within the Ethiopian groups, and between new and early Ethiopian immigrants with Israel and resident Israelis revealed the following: Systolic and diastolic BP were considerably lower in recent immigrants of both sexes than among counterparts residing in Israel for two to three years. The latter group significantly approached, but did not reach, the BP levels of veteran Israelis. A similar comparison of 100 immigrant Ethiopian boarding school children with an Israeli high school population revealed apparently larger differences among the boys than the girls, whose BP was 'adapted' to a greater degree. Differences in relative weight paralleled those identified for BP, with the Quetelet index (QI) progressively higher when comparing new immigrants with earlier ones, and with persons who have lived in Israel for a longer period. Whether the weight differences provide a complete explanation for BP changes cannot be definitely stated, pending prospective data on weight and BP changes. Correlations of BP with anthropometric parameters and pulse rate indicated that weight rather than QI was the stronger correlate of BP in adults, whereas weight and height, but not QI, correlated with BP in adolescent boys. QI correlated with BP in adolescent, apparently sexually mature girls, but not in boys.


Assuntos
Pressão Sanguínea , Hipertensão/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Constituição Corporal , Emigração e Imigração , Fatores Epidemiológicos , Etiópia/etnologia , Feminino , Frequência Cardíaca , Humanos , Israel/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
15.
J Aerosol Med ; 4(3): 189-92, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-10147678

RESUMO

Three possibilities exist, in principle, to apply medication by inhalation: (1) Inhalation from Pressurized Metered Dose Inhalers (2) Direct Inhalation of Dry Powder (3) Inhalation of Nebulized Aqueous Solutions. Chlorofluorocarbons that are necessary for pressurized metered dose inhalers have unwanted environmental properties. Therefore, alternative gases are being developed (HFA-134a and HFA 227) on the premise that pressurized metered dose aerosols in airways therapy have distinct advantages which are reflected in the high acceptance and application of these MDIs worldwide. Dry powder inhalation requires sophisticated devices to provide for exact dosing. For nebulizers the major problem was their size and consequently their restricted use. Multi-dose pocket-size systems are on the market for (1) and (2). For nebulization such a system is currently being introduced. A critical comparison of benefits and disadvantages of the existing drug delivery systems to the airways leads to the conclusion that all three modes will remain essential to cover the therapeutic needs for a wide variety of drugs and patient populations.


Assuntos
Nebulizadores e Vaporizadores , Administração por Inalação , Aerossóis , Desenho de Equipamento , Humanos , Pós
16.
Angiology ; 36(10): 759-65, 1985 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3904536

RESUMO

Twelve patients with pheochromocytoma have shown unusual clinical and laboratory presentation. These include three patients with cardiac manifestations (sick sinus syndrome, obstructive cardiomyopathy and ischemic ECG changes). Two patients with gastrointestinal problems (acute abdomen due to ischemic bowel and constipation). One child with sudden blindness and one, non diabetic patient with polyuria. Laboratory findings included four patients with diabetes mellitus, four patients with hypercalcemia two of them with concomitant hyperreninemia and one patient with hypokalemia. Awareness of the illness leads to the discovery of unusual cases and even a most severely sick patient can make a complete recovery.


Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico , Feocromocitoma/diagnóstico , Adolescente , Neoplasias das Glândulas Suprarrenais/complicações , Neoplasias das Glândulas Suprarrenais/cirurgia , Adulto , Idoso , Cegueira/etiologia , Feminino , Insuficiência Cardíaca/etiologia , Humanos , Hipertensão/etiologia , Masculino , Pessoa de Meia-Idade , Feocromocitoma/complicações , Feocromocitoma/cirurgia , Tomografia Computadorizada por Raios X , Ultrassonografia
17.
J Hypertens Suppl ; 7(1): S53-5, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2709188

RESUMO

Blood pressure was examined in 483 Ethiopian immigrants a few weeks after their arrival in Israel. The results were compared with those from a group of 171 Ethiopian immigrants who came to Israel 2-3 years earlier. Mean blood pressure was significantly higher in the veteran immigrants, whose weight was also greater. Both groups had lower blood pressure than the resident Israeli population.


Assuntos
Pressão Sanguínea , Emigração e Imigração , Hipertensão/etiologia , Adolescente , Adulto , Idoso , Peso Corporal , Etiópia/etnologia , Comportamento Alimentar , Feminino , Humanos , Hipertensão/etnologia , Israel , Estilo de Vida , Masculino , Pessoa de Meia-Idade
18.
Nat Commun ; 5: 4538, 2014 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-25066810

RESUMO

The precise measurement of forces is one way to obtain deep insight into the fundamental interactions present in nature. In the context of neutral antimatter, the gravitational interaction is of high interest, potentially revealing new forces that violate the weak equivalence principle. Here we report on a successful extension of a tool from atom optics--the moiré deflectometer--for a measurement of the acceleration of slow antiprotons. The setup consists of two identical transmission gratings and a spatially resolving emulsion detector for antiproton annihilations. Absolute referencing of the observed antimatter pattern with a photon pattern experiencing no deflection allows the direct inference of forces present. The concept is also straightforwardly applicable to antihydrogen measurements as pursued by the AEgIS collaboration. The combination of these very different techniques from high energy and atomic physics opens a very promising route to the direct detection of the gravitational acceleration of neutral antimatter.

19.
J Environ Radioact ; 102(11): 1032-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21719167

RESUMO

We report results of air monitoring started due to the recent natural catastrophe on 11 March 2011 in Japan and the severe ensuing damage to the Fukushima Dai-ichi nuclear reactor complex. On 17-18 March 2011, we registered the first arrival of the airborne fission products (131)I, (132)I, (132)Te, (134)Cs, and (137)Cs in Seattle, WA, USA, by identifying their characteristic gamma rays using a germanium detector. We measured the evolution of the activities over a period of 23 days at the end of which the activities had mostly fallen below our detection limit. The highest detected activity from radionuclides attached to particulate matter amounted to 4.4 ± 1.3 mBq m(-3) of (131)I on 19-20 March.


Assuntos
Poluentes Radioativos do Ar/análise , Monitoramento Ambiental/métodos , Cinza Radioativa/análise , Liberação Nociva de Radioativos , Radioisótopos/análise , Cidades , Humanos , Japão , Medição de Risco/métodos , Fatores de Tempo , Washington
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