RESUMO
High-precision searches for an electric dipole moment of the neutron (nEDM) require stable and uniform magnetic field environments. We present the recent achievements of degaussing and equilibrating the magnetically shielded room (MSR) for the n2EDM experiment at the Paul Scherrer Institute. We present the final degaussing configuration that will be used for n2EDM after numerous studies. The optimized procedure results in a residual magnetic field that has been reduced by a factor of two. The ultra-low field is achieved with the full magnetic-field-coil system, and a large vacuum vessel installed, both in the MSR. In the inner volume of â¼1.4m3, the field is now more uniform and below 300 pT. In addition, the procedure is faster and dissipates less heat into the magnetic environment, which in turn, reduces its thermal relaxation time from 12h down to 1.5h.
RESUMO
Models that postulate the existence of hidden sectors address contemporary questions, such as the source of baryogenesis and the nature of dark matter. Neutron-to-hidden-neutron oscillations are among the possible mixing processes and have been tested with ultracold neutron storage and passing-through-wall experiments to set constraints on the oscillation period τ_{nn^{'}}. These searches probe the oscillations as a function of the mass splitting due to the neutron-hidden-neutron energy degeneracy. In this work, we present a new limit derived from neutron disappearance in ultracold neutron beam experiments. The overall limit, given by τ_{nn^{'}}>1 s for |δm|∈[2,69] peV(95.45% C.L.), covers the yet unexplored intermediate mass-splitting range and contributes to the ongoing research on hidden sectors.
RESUMO
We present a novel Active Magnetic Shield (AMS), designed and implemented for the n2EDM experiment at the Paul Scherrer Institute. The experiment will perform a high-sensitivity search for the electric dipole moment of the neutron. Magnetic-field stability and control is of key importance for n2EDM. A large, cubic, 5 m side length, magnetically shielded room (MSR) provides a passive, quasi-static shielding-factor of about 105 for its inner sensitive volume. The AMS consists of a system of eight complex, feedback-controlled compensation coils constructed on an irregular grid spanned on a volume of less than 1000 m3 around the MSR. The AMS is designed to provide a stable and uniform magnetic-field environment around the MSR, while being reasonably compact. The system can compensate static and variable magnetic fields up to ±50µT (homogeneous components) and ±5µT/m (first-order gradients), suppressing them to a few µT in the sub-Hertz frequency range. The presented design concept and implementation of the AMS fulfills the requirements of the n2EDM experiment and can be useful for other applications, where magnetically silent environments are important and spatial constraints inhibit simpler geometrical solutions.
RESUMO
We present the magnetically shielded room (MSR) for the n2EDM experiment at the Paul Scherrer Institute, which features an interior cubic volume with each side of length 2.92 m, thus providing an accessible space of 25 m3. The MSR has 87 openings of diameter up to 220 mm for operating the experimental apparatus inside and an intermediate space between the layers for housing sensitive signal processing electronics. The characterization measurements show a remanent magnetic field in the central 1 m3 below 100 pT and a field below 600 pT in the entire inner volume, up to 4 cm to the walls. The quasi-static shielding factor at 0.01 Hz measured with a sinusoidal 2 µT peak-to-peak signal is about 100 000 in all three spatial directions and increases rapidly with frequency to reach 108 above 1 Hz.
RESUMO
This clinical study evaluated the survival of monolithic lithium disilicate (ML) (IPS Emax, Ivoclar Vivadent) restorations bonded to complete-arch CAD/CAM made titanium or zirconia frameworks. Between August 2007 and December 2009, 15 patients (7 female, 8 male; mean age: 56.8 years old) received 30 implant-supported screw-retained rehabilitations with ML restorations cemented to CAD/CAM made titanium (T) (n=6) or zirconia (Z) frameworks (n=24) adhesively (Multilink Automix, RelyX Unicem) and followed up until December 2015. The evaluation protocol involved technical failures (chipping, debonding or fracture of crown/framework, screw loosening), Californian Dental Association (CDA) quality criteria (Romeo: Excellent; Sierra: Acceptable; Tango: Retrievable; Victor: Not acceptable) and biological failures (mucositis, peri-implantitis). Mean observation time was 60.3 months. No implants were lost, and all the prostheses were in situ. Four mechanical failures occurred in the form of minor chipping (n=3 in ML-Z, n=1 in ML-T) and major fracture in ML crown (n=1 in ML-Z). Romeo scores (N=370) decreased until final observation (N=347) and 23 Sierra scores were given to the restorations. Mucositis was observed in 3 patients and peri-implantitis in one patient. Complete-arch implant-borne FDPs made of monolithic lithium disilicate bonded to titanium or zirconia frameworks could be a promising alternative.
Assuntos
Implantes Dentários , Mucosite , Peri-Implantite , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Titânio , Porcelana Dentária , Zircônio , Desenho Assistido por Computador , Coroas , Prótese Dentária Fixada por ImplanteRESUMO
Psychological bias towards, or away from, prior measurements or theory predictions is an intrinsic threat to any data analysis. While various methods can be used to try to avoid such a bias, e.g. actively avoiding looking at the result, only data blinding is a traceable and trustworthy method that can circumvent the bias and convince a public audience that there is not even an accidental psychological bias. Data blinding is nowadays a standard practice in particle physics, but it is particularly difficult for experiments searching for the neutron electric dipole moment (nEDM), as several cross measurements, in particular of the magnetic field, create a self-consistent network into which it is hard to inject a false signal. We present an algorithm that modifies the data without influencing the experiment. Results of an automated analysis of the data are used to change the recorded spin state of a few neutrons within each measurement cycle. The flexible algorithm may be applied twice (or more) to the data, thus providing the option of sequentially applying various blinding offsets for separate analysis steps with independent teams. The subtle manner in which the data are modified allows one subsequently to adjust the algorithm and to produce a re-blinded data set without revealing the initial blinding offset. The method was designed for the 2015/2016 measurement campaign of the nEDM experiment at the Paul Scherrer Institute. However, it can be re-used with minor modification for the follow-up experiment n2EDM, and may be suitable for comparable projects elsewhere.
RESUMO
We present the design of a next-generation experiment, n2EDM, currently under construction at the ultracold neutron source at the Paul Scherrer Institute (PSI) with the aim of carrying out a high-precision search for an electric dipole moment of the neutron. The project builds on experience gained with the previous apparatus operated at PSI until 2017, and is expected to deliver an order of magnitude better sensitivity with provision for further substantial improvements. An overview is of the experimental method and setup is given, the sensitivity requirements for the apparatus are derived, and its technical design is described.
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.
RESUMO
BACKGROUND: Surfactant protein D (SPD) is a member of the collectin family that lines the airway epithelial cells with host defense. However, the role of SPD in the pathogenesis of aspirin-exacerbated respiratory disease (AERD) is still unclear. METHODS: The serum SPD level was measured in patients with AERD (n = 336), those with aspirin-tolerant asthma (ATA, n = 442), and healthy controls (HC, n = 104). Polymorphisms of SFTPD in the study subjects were analyzed. The effect of LTE4 on SPD production through eosinophil infiltration was investigated in BALB/c mice. The protective function of SPD against eosinophils inducing inflammation and remodeling was assessed in vitro/vivo. The potential efficacy of nintedanib against airway remodeling through the production of SPD was evaluated. RESULTS: The serum SPD level was significantly lower (P < .001) in AERD compared with ATA patients, and negatively correlated with fall in FEV1 (%) after lysine-aspirin bronchoprovocation test and/or the urinary LTE4 level. In addition, polymorphism of SFTPD at rs721917 was significantly different in the study subjects (odds ratio, 1.310; 95% confidence intervals, 2.124-3.446; P = .002). LTE4-exposed mice showed an increased eosinophil count with a decreased SPD level in bronchoalveolar lavage fluid. Eosinophils increased α-smooth muscle actin expression in airway epithelial cells, which was attenuated by SPD treatment. Furthermore, nintedanib protected the airway epithelial cells against eosinophils by enhancing the production of SPD. CONCLUSION: The decreased level of SPD in AERD was associated with airway inflammation/remodeling under the eosinophilic condition, suggesting that modulation of SPD may provide a potential benefit in AERD.
Assuntos
Remodelação das Vias Aéreas/efeitos dos fármacos , Asma Induzida por Aspirina/sangue , Eosinófilos/imunologia , Inflamação/tratamento farmacológico , Proteína D Associada a Surfactante Pulmonar/farmacologia , Sistema Respiratório/patologia , Adulto , Animais , Asma Induzida por Aspirina/tratamento farmacológico , Eosinófilos/efeitos dos fármacos , Feminino , Humanos , Indóis/farmacologia , Indóis/uso terapêutico , Inflamação/patologia , Leucotrieno E4/farmacologia , Leucotrieno E4/urina , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Proteína D Associada a Surfactante Pulmonar/sangue , Proteína D Associada a Surfactante Pulmonar/genética , Proteína D Associada a Surfactante Pulmonar/uso terapêuticoRESUMO
The neutrons for science (NFS) facility is a component of SPIRAL-2, the new superconducting linear accelerator built at GANIL in Caen (France). The proton and deuteron beams delivered by the accelerator will allow producing intense neutron fields in the 100 keV-40 MeV energy range. Continuous and quasi-mono-kinetic energy spectra, respectively, will be available at NFS, produced by the interaction of a deuteron beam on a thick Be converter and by the 7Li(p,n) reaction on thin converter. The pulsed neutron beam, with a flux up to two orders of magnitude higher than those of other existing time-of-flight facilities, will open new opportunities of experiments in fundamental research as well as in nuclear data measurements. In addition to the neutron beam, irradiation stations for neutron-, proton- and deuteron-induced reactions will be available for cross-sections measurements and for the irradiation of electronic devices or biological cells. NFS, whose first experiment is foreseen in 2018, will be a very powerful tool for physics, fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors.
Assuntos
Deutério/análise , Desenho de Equipamento , Lítio/química , Nêutrons , Aceleradores de Partículas/instrumentação , Prótons , Simulação por Computador , Doses de RadiaçãoRESUMO
BACKGROUND: A multidrug regimen including isoniazid, rifampicin, pyrazinamide and ethambutol is commonly used as first-line treatment for tuberculosis. However, this regimen can occasionally result in severe adverse drug reactions, such as drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and drug-induced liver injury. The culprit drug and mechanistic basis for the hypersensitive reaction are unknown. OBJECTIVES: To investigate drug-specific T-cell responses in patients with antituberculosis drug (ATD)-induced cutaneous hypersensitivity and its underlying mechanism. METHODS: We enrolled eight patients with ATD-induced maculopapular exanthema and DRESS and performed a lymphocyte transformation test. Subsequently, drug-specific T-cell clones were generated from four of the patients who showed proliferation in response to ATDs. We measured the drug-specific proliferative responses and counted the drug-specific interferon (IFN)-γ/granzyme B-producing cells after drug stimulation. Antihuman leukocyte antigen (HLA) class I and class II blocking antibodies were used to analyse human leukocyte antigen-restricted T-cell responses. RESULTS: Positive proliferative responses to ATDs were mostly found in patients with cutaneous hypersensitivity. Furthermore, we isolated isoniazid/rifampicin-specific T cells from patients, which consisted primarily of CD4+ T cells. Drug-specific CD4+ T cells proliferated and secreted IFN-γ/granzyme B when stimulated with isoniazid or rifampicin, respectively. Isoniazid-responsive T-cell clones did not proliferate in the presence of rifampicin and vice versa. Drug-specific T-cell responses were blocked in the presence of anti-HLA class II antibodies. CONCLUSIONS: This study identifies the presence of isoniazid/rifampicin-specific T cells in patients with ATD-induced maculopapular exanthema and DRESS. Furthermore, it highlights the important role of drug-specific T-cell immune responses in the pathogenesis of these reactions.
Assuntos
Antituberculosos/efeitos adversos , Linfócitos T CD4-Positivos/imunologia , Síndrome de Hipersensibilidade a Medicamentos/imunologia , Exantema/induzido quimicamente , Imunidade Celular/imunologia , Adulto , Antituberculosos/imunologia , Exantema/imunologia , Feminino , Antígenos HLA/efeitos dos fármacos , Antígenos HLA/imunologia , Humanos , Isoniazida/efeitos adversos , Isoniazida/imunologia , Masculino , Pessoa de Meia-Idade , Rifampina/efeitos adversos , Rifampina/imunologiaRESUMO
BACKGROUND: To date, there has been no reliable in vitro test to diagnose aspirin-exacerbated respiratory disease (AERD). OBJECTIVE: To investigate potential diagnostic biomarkers for AERD using metabolomic analysis. METHODS: An untargeted profile of serum from asthmatics in the first cohort (group 1) comprising 45 AERD, 44 patients with aspirin-tolerant asthma (ATA), and 28 normal controls was developed using the ultra-high-performance liquid chromatography (UHPLC)/Q-ToF MS system. Metabolites that discriminate AERD from ATA were quantified in both serum and urine, which were collected before (baseline) and after the lysine-aspirin bronchoprovocation test (Lys-ASA BPT). The serum metabolites were validated in the second cohort (group 2) comprising 50 patients with AERD and 50 patients with ATA. RESULTS: A clear discrimination of metabolomes was found between patients with AERD and ATA. In group 1, serum levels of LTE4 and LTE4 /PGF2 α ratio before and after the Lys-ASA BPT were significantly higher in patients with AERD than in patients with ATA (P < 0.05 for each), and urine baseline levels of these two metabolites were significantly higher in patients with AERD. Significant differences of serum metabolite levels between patients with AERD and ATA were replicated in group 2 (P < 0.05 for each). Moreover, serum baseline levels of LTE4 and LTE4 /PGF2 α ratio discriminated AERD from ATA with 70.5%/71.6% sensitivity and 41.5%/62.8% specificity, respectively (AUC = 0.649 and 0.732, respectively P < 0.001 for each). Urine baseline LTE4 levels were significantly correlated with the fall in FEV1 % after the Lys-ASA BPT in patients with AERD (P = 0.008, r = 0.463). CONCLUSIONS AND CLINICAL RELEVANCE: Serum metabolite level of LTE4 and LTE4 /PGF2 α ratio was identified as potential in vitro diagnostic biomarkers for AERD using the UHPLC/Q-ToF MS system, which were closely associated with major pathogenetic mechanisms underlying AERD.
Assuntos
Asma Induzida por Aspirina/diagnóstico , Asma Induzida por Aspirina/metabolismo , Biomarcadores , Metaboloma , Metabolômica , Adolescente , Adulto , Idoso , Asma Induzida por Aspirina/sangue , Asma Induzida por Aspirina/imunologia , Progressão da Doença , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Mediadores da Inflamação/sangue , Mediadores da Inflamação/metabolismo , Contagem de Leucócitos , Masculino , Metabolômica/métodos , Pessoa de Meia-Idade , Neutrófilos , Adulto JovemRESUMO
BACKGROUND: Autophagy and neutrophil extracellular DNA traps (NETs) are implicated in asthma; however, their roles in asthma pathogenesis have not been elucidated. OBJECTIVES: We compared autophagy and NET production levels from peripheral blood neutrophils (PBNs) of patients with severe asthma (SA) and non-severe asthma (NSA). Additionally, we investigated the inflammatory effects of NETs on human airway epithelial cells (AECs) and peripheral blood eosinophils (PBEs). METHODS: Peripheral blood neutrophils from patients with SA (n = 30) and NSA (n = 38) were treated with interleukin (IL)-8 (100 ng/mL). Autophagy (light chain 3-II expression) and NET production levels were evaluated by Western blot, immunofluorescence microscopy, and PicoGreen assay. The effects of NETs on AECs were assessed by investigating cell death, cell detachment, expression of occludin and claudin-1, and IL-8 production; the effects of NETs on PBEs were examined by investigating the activation and release of eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN). RESULTS: Untreated and IL-8-treated PBNs from the SA group produced higher autophagy and NET levels compared with those from the NSA group (P < 0.01). IL-8 increased autophagy and NET levels in PBNs from the SA group, but not from the NSA group. NET levels were correlated with autophagy levels in PBNs (P < 0.001). IL-8-induced NET production levels negatively were correlated with FEV1/FVC (r = -0.700, P = 0.016). NETs induced cell death, detachment, degradation of occludin and claudin-1, and IL-8 production from AECs. Higher levels of NET-induced ECP and EDN were released from PBEs in SA compared with NSA groups. CONCLUSIONS AND CLINICAL RELEVANCE: Neutrophil autophagy and NETs could enhance asthma severity by damaging airway epithelium and triggering inflammatory responses of AECs and PBEs. Modulating neutrophil autophagy and NET production may be a new target therapy for SA.
Assuntos
Asma/etiologia , Autofagia , Armadilhas Extracelulares/imunologia , Neutrófilos/imunologia , Adulto , Asma/metabolismo , Asma/patologia , Linhagem Celular , Quimiotaxia/imunologia , Eosinófilos/imunologia , Eosinófilos/metabolismo , Células Epiteliais , Armadilhas Extracelulares/genética , Armadilhas Extracelulares/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Proteólise , Proteínas de Junções Íntimas/metabolismoRESUMO
BACKGROUND: Clinical presentation of nonsteroidal anti-inflammatory drugs exacerbated respiratory disease (NERD) is found to be heterogeneous. This study classified phenotypic clusters to determine NERD subtypes. METHODS: We performed two-step cluster analysis using urticaria, chronic rhinosinusitis (CRS), and atopy, in a NERD cohort comprising 302 patients. Asthma exacerbation was defined as receiving at least one burst of intravenous steroid treatment and/or at least two bursts of oral steroid use (≥ 45 mg/3 days) per year. The possession rate of anti-asthmatic medications was estimated during the follow-up period. RESULTS: There were four subtypes: subtype 1 (NERD with CRS/atopy and no urticaria), subtype 2 (NERD with CRS and no urticaria/atopy), subtype 3 (NERD without CRS/urticaria), and subtype 4 (NERD with urticaria). Significant differences were found between the four subtypes in the female proportion, baseline FEV1%, serum total IgE level, and sputum/peripheral eosinophil count. A higher frequency of asthma exacerbations was noted in subtype 1 compared to subtype 3. The possession rates of medium- to high-dose inhaled corticosteroids/long-acting beta2 -agonists showed significant differences among the four subtypes. Metabolomic analysis showed that the four subtypes of NERD had a higher serum leukotriene E4 (LTE4) level than those with aspirin-tolerant asthma. The patients with subtypes 1 and 3 had a higher urine LTE4 level than those with subtype 2. CONCLUSION: We found four distinct subtypes with different clinical/biochemical findings and asthma exacerbations in a NERD cohort. These findings suggest that stratified strategies by applying subtype classification may help achieve better outcomes in the management of NERD.
Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Fenótipo , Doenças Respiratórias/diagnóstico , Doenças Respiratórias/etiologia , Adulto , Idade de Início , Anti-Inflamatórios não Esteroides/uso terapêutico , Asma/diagnóstico , Asma/epidemiologia , Asma/etiologia , Asma/metabolismo , Biomarcadores , Análise por Conglomerados , Progressão da Doença , Feminino , Seguimentos , Humanos , Mediadores da Inflamação/metabolismo , Contagem de Leucócitos , Leucotrieno E4/sangue , Leucotrieno E4/urina , Masculino , Metaboloma , Metabolômica/métodos , Pessoa de Meia-Idade , Testes de Função Respiratória , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/metabolismoRESUMO
The present paper summarizes the results obtained from the past few years in the framework of the Enhanced Multi-Ionization of short-Lived Isotopes for Eurisol (EMILIE) project. The EMILIE project aims at improving the charge breeding techniques with both Electron Cyclotron Resonance Ion Sources (ECRIS) and Electron Beam Ion Sources (EBISs) for European Radioactive Ion Beam (RIB) facilities. Within EMILIE, an original technique for debunching the beam from EBIS charge breeders is being developed, for making an optimal use of the capabilities of CW post-accelerators of the future facilities. Such a debunching technique should eventually resolve duty cycle and time structure issues which presently complicate the data-acquisition of experiments. The results of the first tests of this technique are reported here. In comparison with charge breeding with an EBIS, the ECRIS technique had lower performance in efficiency and attainable charge state for metallic ion beams and also suffered from issues related to beam contamination. In recent years, improvements have been made which significantly reduce the differences between the two techniques, making ECRIS charge breeding more attractive especially for CW machines producing intense beams. Upgraded versions of the Phoenix charge breeder, originally developed by LPSC, will be used at SPES and GANIL/SPIRAL. These two charge breeders have benefited from studies undertaken within EMILIE, which are also briefly summarized here.
RESUMO
BACKGROUND: Autophagy and genetic predisposition have been suggested to potentially play roles in the development of asthma. However, little is known about the role of autophagy in the pathogenesis of severe asthma. OBJECTIVE: We compared autophagy in the sputum granulocytes, peripheral blood cells (PBCs) and peripheral blood eosinophils (PBEs) between patients with severe asthma and those with non-severe asthma and investigated the functional effects of autophagy. METHODS: We enrolled 36 patients with severe asthma, 14 with non-severe asthma and 23 normal healthy controls in this study. Sputum granulocytes, PBCs and PBEs were isolated from each subject. Autophagy was evaluated based on the expression of microtubule-associated protein light chain 3 (LC3) by Western blot, confocal microscopy, transmission electron microscopy and flow cytometry. IL-8 levels were measured by ELISA. To induce autophagy, HL-60 cells, human primary small airway epithelial cells (SAECs) and A549 cells were treated with IL-5, IL-1ß and TNF-α. To inhibit autophagy, PI3K inhibitors (LY29400 and 3-methyladenine [3-MA]) and hydroxychloroquine (HCQ) were used. Knockdown of ATG5 and Beclin-1 was performed in A549 cells, and the therapeutic effects of dexamethasone were evaluated. RESULTS: Higher autophagy levels were noted in sputum granulocytes, PBCs and PBEs from patients with severe asthma than from patients with non-severe asthma and healthy controls (P < 0.05 for all). IL-5 increased autophagy levels in both PBCs and PBEs (P < 0.05). 3-MA attenuated the increased expression of LC3-II and eosinophil cationic protein in HL-60 cells induced by IL-5 (P = 0.034 for both). Dexamethasone did not affect autophagy levels in PBEs. IL-1ß increased LC3-II expression and IL-8 production (P < 0.01) in SAECs, and this was attenuated by LY294002, 3-MA, HCQ and knockdown of ATG5 and Beclin-1 (in A549 cells) (P < 0.01). CONCLUSIONS AND CLINICAL RELEVANCE: Autophagy could play a role in the pathogenesis of severe asthma. Autophagy modulation may be a novel therapeutic target for conventional therapy-resistant severe asthma.
Assuntos
Asma/etiologia , Asma/metabolismo , Autofagia , Leucócitos/imunologia , Leucócitos/metabolismo , Escarro/citologia , Escarro/imunologia , Adulto , Proteínas Reguladoras de Apoptose/genética , Asma/diagnóstico , Asma/terapia , Proteína 5 Relacionada à Autofagia , Proteína Beclina-1 , Estudos de Casos e Controles , Linhagem Celular , Citocinas , Feminino , Volume Expiratório Forçado , Técnicas de Silenciamento de Genes , Granulócitos/imunologia , Granulócitos/metabolismo , Humanos , Imunoglobulina E/imunologia , Contagem de Leucócitos , Masculino , Proteínas de Membrana/genética , Proteínas Associadas aos Microtúbulos/genética , Pessoa de Meia-Idade , Fagossomos/metabolismo , Índice de Gravidade de Doença , Adulto JovemRESUMO
We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a |B0|=1 µT magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic field provides an excellent method by which to reconstruct the energy spectrum of a confined ensemble of neutrons. The method takes advantage of the relative dephasing of spins arising from a gravitationally induced striation of stored UCNs of different energies, and also permits an improved determination of the vertical magnetic-field gradient with an exceptional accuracy of 1.1 pT/cm. This novel combination of a well-known nuclear resonance method and gravitationally induced vertical striation is unique in the realm of nuclear and particle physics and should prove to be invaluable for the assessment of systematic effects in precision experiments such as searches for an electric dipole moment of the neutron or the measurement of the neutron lifetime.
Assuntos
Gravitação , Modelos Teóricos , Nêutrons , Temperatura Baixa , CinéticaRESUMO
We present a magnetometer based on optically pumped Cs atoms that measures the magnitude and direction of a 1 µT magnetic field. Multiple circularly polarized laser beams were used to probe the free spin precession of the Cs atoms. The design was optimized for long-time stability and achieves a scalar resolution better than 300 fT for integration times ranging from 80 ms to 1000 s. The best scalar resolution of less than 80 fT was reached with integration times of 1.6 to 6 s. We were able to measure the magnetic field direction with a resolution better than 10 µrad for integration times from 10 s up to 2000 s.
RESUMO
BACKGROUND: Body mass index (BMI) has an impact on survival outcome in patients treated with aromatase inhibitors (AIs). Obesity is associated with an increased body aromatisation and may be a cause of insufficient estradiol depletion. METHODS: Sixty-eight postmenopausal oestrogen receptor-positive patients with early breast cancer were prospectively included in this study. Follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol were analysed immediately in the clinical routine lab and in a dedicated central lab before (T1) and 3 months after start with aromatase inhibitors (T2). RESULTS: A total of 40 patients were normal or overweight (non-obese: BMI 18.5-29.9 kg m(-2)) and 28 were obese (BMI ≥ 30 kg m(-2)). Aromatase inhibitors significantly suppressed estradiol serum levels (T1: 19.5 pg ml(-1), T2: 10.5 pg ml(-1), P<0.01) and increased FSH serum levels (T1: 70.2 mIU ml(-1), T2: 75.7 mIU ml(-1), P<0.05). However, after 3 months of AI treatment, estradiol levels of obese patients were nonsignificantly higher compared with non-obese patients (12.5 pg ml(-1) vs 9.0 pg ml(-1), P=0.1). This difference was reflected by significantly lower FSH serum levels in obese compared with non-obese patients (65.5 mIU ml(-1) vs 84.6 mIU ml(-1), P<0.01). The significant effects of BMI on FSH serum levels could be detected both in the routine as well as in the dedicated central lab. CONCLUSION: Aromatase inhibitors are less efficient at suppressing estradiol serum levels in obese when compared with non-obese women.