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1.
J Frailty Aging ; 13(1): 21-30, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38305439

RESUMO

BACKGROUND AND OBJECTIVE: This study examined the relationship between body mass index (BMI) and sarcopenia with oral function decline in older patients as well as whether a combination of underweight BMI and sarcopenia was associated with decreased oral function in individuals with conservative restorative and prosthetic treatment for masticatory disorders. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study included 290 older Japanese patients who regularly attended a general dental clinic. A detailed examination of oral function, sarcopenia, and BMI according to the Asian Working Group for Sarcopenia 2019 criteria was conducted for patients aged 65 years. This study used odds ratios as an epidemiological measure in the cross-sectional survey. RESULTS: Multinomial logistic regression analysis showed that the number of remaining teeth and tongue pressure was associated with both ideal and overweight BMI in individuals with sarcopenia when compared to healthy individuals. The underweight BMI plus sarcopenia group was associated with tongue and lip motor function [ka] sound test, swallowing function, and the presence of oral hypofunction. DISCUSSION: Our findings indicated that various aspects of oral function were impaired in community-dwelling older adult Japanese patients with sarcopenia and underweight BMI. Notably, among older adults with sarcopenia, both obese and thin patients exist, suggesting that distinct pathophysiological mechanisms influence oral function. CONCLUSION: The above findings support the hypothesis that the coexistence of sarcopenia and underweight BMI is associated with poor oral function. Regular oral function assessments and weight measurements in general dental practice can aid the prompt identification of sarcopenia and reduced swallowing function and can facilitate early intervention. The presence of sarcopenia and impaired swallowing function should be considered in patients with underweight BMI, reduced [ka] sound, and low tongue pressure following a thorough oral function examination.


Assuntos
Sarcopenia , Humanos , Idoso , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Índice de Massa Corporal , Estudos Transversais , Língua , Japão/epidemiologia , Magreza/epidemiologia , Pressão , Clínicas Odontológicas
2.
Rev Sci Instrum ; 94(11)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37972020

RESUMO

Currently, the world's only source of low-energy antiprotons is the AD/ELENA facility located at CERN. To date, all precision measurements on single antiprotons have been conducted at this facility and provide stringent tests of fundamental interactions and their symmetries. However, magnetic field fluctuations from the facility operation limit the precision of upcoming measurements. To overcome this limitation, we have designed the transportable antiproton trap system BASE-STEP to relocate antiprotons to laboratories with a calm magnetic environment. We anticipate that the transportable antiproton trap will facilitate enhanced tests of charge, parity, and time-reversal invariance with antiprotons and provide new experimental possibilities of using transported antiprotons and other accelerator-produced exotic ions. We present here the technical design of the transportable trap system. This includes the transportable superconducting magnet, the cryogenic inlay consisting of the trap stack and detection systems, and the differential pumping section to suppress the residual gas flow into the cryogenic trap chamber.

3.
Rev Sci Instrum ; 94(10)2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37874231

RESUMO

We present the design and characterization of a cryogenic window based on an ultra-thin aluminized biaxially oriented polyethylene terephthalate foil at T < 10 K, which can withstand a pressure difference larger than 1 bar at a leak rate <1×10-9 mbar l/s. Its thickness of ∼1.7 µm makes it transparent to various types of particles over a broad energy range. To optimize the transfer of 100 keV antiprotons through the window, we tested the degrading properties of different aluminum coated polymer foils of thicknesses between 900 and 2160 nm, concluding that 1760 nm foil decelerates antiprotons to an average energy of 5 keV. We have also explicitly studied the permeation as a function of coating thickness and temperature and have performed extensive thermal and mechanical endurance and stress tests. Our final design integrated into the experiment has an effective open surface consisting of seven holes with a diameter of 1 mm and will transmit up to 2.5% of the injected 100 keV antiproton beam delivered by the Antiproton Decelerator and Extra Low ENergy Antiproton ring facility of CERN.

4.
Artigo em Inglês | MEDLINE | ID: mdl-37288385

RESUMO

Abstract: The BASE collaboration at the antiproton decelerator/ELENA facility of CERN compares the fundamental properties of protons and antiprotons with ultra-high precision. Using advanced Penning trap systems, we have measured the proton and antiproton magnetic moments with fractional uncertainties of 300 parts in a trillion (p.p.t.) and 1.5 parts in a billion (p.p.b.), respectively. The combined measurements improve the resolution of the previous best test in that sector by more than a factor of 3000. Very recently, we have compared the antiproton/proton charge-to-mass ratios with a fractional precision of 16 p.p.t., which improved the previous best measurement by a factor of 4.3. These results allowed us also to perform a differential matter/antimatter clock comparison test to limits better than 3%. Our measurements enable us to set limits on 22 coefficients of CPT- and Lorentz-violating standard model extensions (SME) and to search for potentially asymmetric interactions between antimatter and dark matter. In this article, we review some of the recent achievements and outline recent progress towards a planned improved measurement of the antiproton magnetic moment with an at least tenfold improved fractional accuracy.

5.
Rev Sci Instrum ; 93(9): 093303, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182508

RESUMO

We describe a newly developed polytetrafluoroethylene/copper capacitor driven by a cryogenic piezoelectric slip-stick stage and demonstrate with the chosen layout cryogenic capacitance tuning of ≈60 pF at ≈10 pF background capacitance. Connected to a highly sensitive superconducting toroidal LC circuit, we demonstrate tuning of the resonant frequency between 345 and 685 kHz, at quality factors Q > 100 000. Connected to a cryogenic ultra low noise amplifier, a frequency tuning range between 520 and 710 kHz is reached, while quality factors Q > 86 000 are achieved. This new device can be used as a versatile image current detector in high-precision Penning-trap experiments or as an LC-circuit-based haloscope detector to search for the conversion of axion-like dark matter to radio-frequency photons. This new development increases the sensitive detection bandwidth of our axion haloscope by a factor of ≈1000.

6.
Int J Tuberc Lung Dis ; 26(5): 412-418, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35505476

RESUMO

SETTING: Diagnosis of Mycobacterium avium complex pulmonary disease (MAC-PD) requires positive culture of expectorated sputum or specimens acquired by bronchoscopy. Whether patients diagnosed using bronchoscopy have milder disease and milder progression than those diagnosed using sputum remains uncertain.OBJECTIVE: To clarify whether disease severity and progression differ according to the diagnostic method.METHODS: We retrospectively analysed 92 patients with MAC-PD. We compared characteristics of patients and disease progression according to the diagnostic methods used: sputum or bronchoscopy. Additionally, we investigated the impact of these methods on disease progression using multivariate analysis.RESULTS: Patients diagnosed using sputum were younger than those diagnosed using bronchoscopy; however, there were small differences from the viewpoint of clinical practice in disease severity, and estimated progression-free survival rate did not differ significantly. The predictors of disease progression were disease forms other than non-cavitary nodular/bronchiectatic disease, hypoalbuminemia and severe radiographic scores.CONCLUSION: The diagnostic methods had no significant impact on disease severity and disease progression of MAC-PD. If the diagnosis cannot be established by sputum culture or if sputum cannot be obtained in the patients with risk factors for disease progression, bronchoscopy would be useful to provide opportunity of treatment for MAC-PD.


Assuntos
Pneumopatias , Infecção por Mycobacterium avium-intracellulare , Progressão da Doença , Humanos , Pneumopatias/diagnóstico , Complexo Mycobacterium avium , Infecção por Mycobacterium avium-intracellulare/diagnóstico , Infecção por Mycobacterium avium-intracellulare/microbiologia , Estudos Retrospectivos
7.
Nature ; 601(7891): 53-57, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34987217

RESUMO

The standard model of particle physics is both incredibly successful and glaringly incomplete. Among the questions left open is the striking imbalance of matter and antimatter in the observable universe1, which inspires experiments to compare the fundamental properties of matter/antimatter conjugates with high precision2-5. Our experiments deal with direct investigations of the fundamental properties of protons and antiprotons, performing spectroscopy in advanced cryogenic Penning trap systems6. For instance, we previously compared the proton/antiproton magnetic moments with 1.5 parts per billion fractional precision7,8, which improved upon previous best measurements9 by a factor of greater than 3,000. Here we report on a new comparison of the proton/antiproton charge-to-mass ratios with a fractional uncertainty of 16 parts per trillion. Our result is based on the combination of four independent long-term studies, recorded in a total time span of 1.5 years. We use different measurement methods and experimental set-ups incorporating different systematic effects. The final result, [Formula: see text], is consistent with the fundamental charge-parity-time reversal invariance, and improves the precision of our previous best measurement6 by a factor of 4.3. The measurement tests the standard model at an energy scale of 1.96 × 10-27 gigaelectronvolts (confidence level 0.68), and improves ten coefficients of the standard model extension10. Our cyclotron clock study also constrains hypothetical interactions mediating violations of the clock weak equivalence principle (WEPcc) for antimatter to less than 1.8 × 10-7, and enables the first differential test of the WEPcc using antiprotons11. From this interpretation we constrain the differential WEPcc-violating coefficient to less than 0.030.

8.
Acta Gastroenterol Belg ; 84(1): 57-63, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33639694

RESUMO

Background: The aim of this retrospective study was to determine whether tolvaptan treatment reduces the amount of albumin administered, volume of ascites removed, and frequency of paracentesis procedures in patients with decompensated cirrhosis with uncontrolled ascites with conventional diuretics. Patients and methods: The control (C) group included patients treated with conventional diuretics. The tolvaptan (T) group included patients treated with both tolvaptan and conventional diuretics. Both groups were matched according to baseline parameters. The amount of albumin administered, volume of ascites removed, and frequency of paracentesis within 30 days of onset of uncontrolled ascites were compared between the two groups. Results: After matching, 74 patients (C=37, T=37) were included. Baseline parameters (C vs. T group) were as follows: age, 69.5 ± 9.3 vs. 70.4 ± 11.0 years (p = 0.702) ; males, 24 (64.9%) vs. 25 (67.6%) (p = 0.999) ; patients with hepatocellular carcinoma, 17 (45.9%) vs. 18 (48.6%) (p = 0.999) ; serum albumin levels at treatment initiation, 2.76 ± 0.48 vs. 2.73 ± 0.49 g/dL (p = 0.773), and serum creatinine levels at treatment initiation, 1.18 ± 1.23 vs. 1.09 ± 0.48 g/dL (p = 0.679). In the C vs. T groups, respectively, mean amount of albumin administered was 51.0 ± 31.4 vs. 33.4 ± 29.8 g/month (p = 0.016) ; mean volume of ascites removed was 2,905 ± 4,921 vs. 1,824 ± 3,185 mL/month (p = 0.266) ; and mean frequency of paracentesis was 0.92 ± 1.46 vs. 0.89 ± 1.45 procedures (p = 0.937). Conclusions: Tolvaptan reduced the use of albumin infusion in patients with decompensated cirrhosis and was effective and acceptable for uncontrolled ascites.


Assuntos
Ascite , Neoplasias Hepáticas , Idoso , Albuminas , Ascite/tratamento farmacológico , Ascite/etiologia , Estudos de Coortes , Humanos , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Estudos Retrospectivos , Tolvaptan
9.
Geophys Res Lett ; 47(15): e2020GL088803, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32999519

RESUMO

We investigate the forces and atmosphere-ionosphere coupling that create atmospheric dynamo currents using two rockets launched nearly simultaneously on 4 July 2013 from Wallops Island (USA), during daytime Sq conditions with ΔH of -30 nT. One rocket released a vapor trail observed from an airplane which showed peak velocities of >160 m/s near 108 km and turbulence coincident with strong unstable shear. Electric and magnetic fields and plasma density were measured on a second rocket. The current density peaked near 110 km exhibiting a spiral pattern with altitude that mirrored that of the winds, suggesting the dynamo is driven by tidal forcing. Such stratified currents are obscured in integrated ground measurements. Large electric fields produced a current opposite to that driven by the wind, believed created to minimize the current divergence. Using the observations, we solve the dynamo equation versus altitude, providing a new perspective on the complex nature of the atmospheric dynamo.

10.
Lett Appl Microbiol ; 71(6): 560-566, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32852051

RESUMO

Along with progress in globalization of society, the spread of infectious diseases has accelerated worldwide. The deployment of highly sensitive genetic tests is essential for early diagnosis and early containment of potential outbreaks and epidemics, as well as routine surveillance, although tedious and expensive nucleic acid extraction steps represent a major drawback. Here we developed a simple and rapid DNA extraction method, named as an EZ-Fast kit, applicable to the field setting. The kit does not require advanced laboratory equipment or expensive DNA extraction kits and achieves crude DNA extraction within 10 min at extremely low cost and can easily be performed in field settings. When combined with real-time PCR and LAMP analyses, the performance of the POCT, using 183 bovine blood samples, was similar to that of the existing DNA extraction method: 92·5% (135/146) (real-time PCR) and 93·7% (133/142) (LAMP) diagnostic sensitivities, and 100% diagnostic specificities. The developed POCT provides a powerful tool to facilitate on-site diagnosis in a field setting.


Assuntos
DNA/genética , Testes Diagnósticos de Rotina/métodos , Leucose Enzoótica Bovina/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Bovinos , DNA/sangue , Leucose Enzoótica Bovina/sangue , Leucose Enzoótica Bovina/genética , Técnicas de Amplificação de Ácido Nucleico/veterinária , Testes Imediatos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Sensibilidade e Especificidade
11.
Nature ; 575(7782): 310-314, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31723290

RESUMO

Astrophysical observations indicate that there is roughly five times more dark matter in the Universe than ordinary baryonic matter1, and an even larger amount of the Universe's energy content is attributed to dark energy2. However, the microscopic properties of these dark components remain unknown. Moreover, even ordinary matter-which accounts for five per cent of the energy density of the Universe-has yet to be understood, given that the standard model of particle physics lacks any consistent explanation for the predominance of matter over antimatter3. Here we present a direct search for interactions of antimatter with dark matter and place direct constraints on the interaction of ultralight axion-like particles (dark-matter candidates) with antiprotons. If antiprotons have a stronger coupling to these particles than protons do, such a matter-antimatter asymmetric coupling could provide a link between dark matter and the baryon asymmetry in the Universe. We analyse spin-flip resonance data in the frequency domain acquired with a single antiproton in a Penning trap4 to search for spin-precession effects from ultralight axions, which have a characteristic frequency governed by the mass of the underlying particle. Our analysis constrains the axion-antiproton interaction parameter to values greater than 0.1 to 0.6 gigaelectronvolts in the mass range from 2 × 10-23 to 4 × 10-17 electronvolts, improving the sensitivity by up to five orders of magnitude compared with astrophysical antiproton bounds. In addition, we derive limits on six combinations of previously unconstrained Lorentz- and CPT-violating terms of the non-minimal standard model extension5.

12.
Lett Appl Microbiol ; 69(3): 155-160, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31216592

RESUMO

Mycobacterium avium causes atypical mycobacterial infection in humans and animals worldwide. M. avium comprises the subspecies avium (MAA), hominissuis (MAH), silvaticum (MAS) and paratuberculosis (MAP). The M. avium complex (MAC), comprising M. avium and M. intracellulare, causes opportunistic infections of humans. M. avium subsp. avium (MAA) mainly causes avian tuberculosis while subsp. hominissuis (MAH) mainly infects pig. Distinguishing between these two subspecies is essential to the effective control of these atypical mycobacterial infections and minimization of the resulting economic loss. For this purpose, we developed a loop-mediated isothermal amplification (LAMP) assay that rapidly and sensitively detects and differentiates MAA and MAH. This MAA-LAMP assay targeting IS901 correctly detected four MAA isolates but did not detect 27 MAH and 19 non-MAA/non-MAH mycobacterial isolates. The MAAH-LAMP assay targeting IS1245 detected four MAA and 27 MAH isolates but not the other 19 mycobacterial isolates. We believe that implementation of this LAMP assay will significantly improve public health and safety. SIGNIFICANCE AND IMPACT OF THE STUDY: Mycobacterium avium, which is pathogenic for humans and animals, represents a continuing threat to public health and safety and to food production. Therefore, improved methods are urgently required to readily and efficiently identify M. avium subspecies. Compared with conventional PCR methods, the LAMP assay herein developed more rapidly detects and better distinguishes between two major M. avium subspecies that cause disease of pig. Importantly, this highly accurate and sensitive LAMP assay detects mycobacterial DNAs using real-time fluorescence or the unaided eye with a colour-change dye, making it ideal for translation to the clinic and slaughterhouse.


Assuntos
Complexo Mycobacterium avium/isolamento & purificação , Mycobacterium avium/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Animais , Inocuidade dos Alimentos/métodos , Humanos , Mycobacterium avium/classificação , Mycobacterium avium/genética , Complexo Mycobacterium avium/classificação , Complexo Mycobacterium avium/genética , Carne Vermelha/microbiologia , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/microbiologia
13.
Phys Rev Lett ; 122(4): 043201, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30768304

RESUMO

We report on the first detailed study of motional heating in a cryogenic Penning trap using a single antiproton. Employing the continuous Stern-Gerlach effect we observe cyclotron quantum transition rates of 6(1) quanta/h and an electric-field noise spectral density below 7.5(3.4)×10^{-20} V^{2} m^{-2} Hz^{-1}, which corresponds to a scaled noise spectral density below 8.8(4.0)×10^{-12} V^{2} m^{-2}, results which are more than 2 orders of magnitude smaller than those reported by other ion-trap experiments.

14.
Clin Exp Dermatol ; 43(6): 703-707, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29797478

RESUMO

Although numerous infective agents, including varicella zoster virus (VZV), have been described in association with pityriasis lichenoides et varioliformis acuta (PLEVA) and pityriasis lichenoides chronica (PLC), none has been identified consistently in these lesions. We sought to immunohistochemically identify VZV glycoprotein (g)E antigens in the vascular endothelium in PLEVA and PLC lesions, based on our previous observation that gE was detected in the vascular endothelium and eccrine unit up until 2 months and 2.5, respectively, years after herpes zoster (HZ) infection. In five of the six cases of PLEVA, VZV gE was identified in the endothelial cells and eccrine epithelium, as observed in HZ lesions, whereas VZV gE was detected in only one of seven patients with PLC. None of the patients with PLEVA who had VZV gE-positive vascular endothelial cells had experienced previous episodes of HZ. VZV may be one of the aetiological agents for PLEVA while other aetiological factors could exist in PLC.


Assuntos
Herpesvirus Humano 3/isolamento & purificação , Pitiríase Liquenoide/virologia , Infecção pelo Vírus da Varicela-Zoster/complicações , Adolescente , Adulto , Feminino , Humanos , Masculino , Pitiríase Liquenoide/patologia , Estudos Retrospectivos , Proteínas do Envelope Viral/isolamento & purificação
15.
Vet J ; 235: 42-46, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29704937

RESUMO

A retrospective cohort study was conducted to investigate risk factors for the failure of Thoroughbred racehorses to return to racing after an injury of the superficial digital flexor tendon (SDFT). Successful return was defined as the completion of five or more races after SDFT injury. The official Japan Racing Association (JRA) medical records of racehorses with a core-type SDFT injury were reviewed for clinical variables related to the characteristics of the horse and the severity of SDFT injuries at the time of diagnosis. Data on racing outcomes were obtained from the official JRA racing database. Risk factors were screened using univariable logistic regression and subsequent multivariable model building. Forty-nine of 346 (14.2%) horses successfully returned to racing after SDFT injuries. Multivariable model building revealed that an increase in the total number of injured zones (defined as the total number of zones in which the injured hypoechoic area was observed at the time of ultrasonographic diagnosis of SDFT injury) was associated with an increased risk of failure to return to racing after SDFT injury. Horse characteristics, such as age, body mass and sex, were not associated with a successful return to racing. In the rehabilitation of cases with larger (longer) lesions, more effective and careful medical management may be needed for an improvement in the athletic outcomes.


Assuntos
Doenças dos Cavalos/fisiopatologia , Corrida , Traumatismos dos Tendões/veterinária , Animais , Composição Corporal , Estudos de Coortes , Feminino , Cavalos , Masculino , Estudos Retrospectivos , Fatores de Risco , Traumatismos dos Tendões/diagnóstico por imagem , Traumatismos dos Tendões/fisiopatologia , Tendões , Ultrassonografia/veterinária
16.
Philos Trans A Math Phys Eng Sci ; 376(2116)2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29459412

RESUMO

The goal of the ASACUSA-CUSP collaboration at the Antiproton Decelerator of CERN is to measure the ground-state hyperfine splitting of antihydrogen using an atomic spectroscopy beamline. A milestone was achieved in 2012 through the detection of 80 antihydrogen atoms 2.7 m away from their production region. This was the first observation of 'cold' antihydrogen in a magnetic field free region. In parallel to the progress on the antihydrogen production, the spectroscopy beamline was tested with a source of hydrogen. This led to a measurement at a relative precision of 2.7×10-9 which constitutes the most precise measurement of the hydrogen hyperfine splitting in a beam. Further measurements with an upgraded hydrogen apparatus are motivated by CPT and Lorentz violation tests in the framework of the Standard Model Extension. Unlike for hydrogen, the antihydrogen experiment is complicated by the difficulty of synthesizing enough cold antiatoms in the ground state. The first antihydrogen quantum states scan at the entrance of the spectroscopy apparatus was realized in 2016 and is presented here. The prospects for a ppm measurement are also discussed.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'.

17.
Arch Gerontol Geriatr ; 74: 106-111, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29080497

RESUMO

OBJECTIVE: In the elderly and patients with dysphagia, masticatory problems often cause aspiration or choking. Although simple methods to predict aspiration and silent aspiration exist, methods for evaluating the masticatory function of patients with dysphagia are lacking. Accordingly, we developed a simple test to assess the chewing and swallowing ability of patients with dysphagia. METHODS: One hundred and five patients with dysphagia were included. We used the Saku-Saku Test (SST), in which patients were asked to eat a rice cracker, and evaluated the quality of mandibular rotation during mastication. We studied the participants' ability to grind, aggregate, and swallow using videoendoscopic evaluation (VE) and investigated its association with mandibular rotation. RESULTS: The SST showed good reliability between two examiners, with a kappa coefficient of 0.80. 92.4% of the patients ate the rice cracker without aspiration. The SST showed a high sensitivity of 73.3% and specificity of 93.3% for the degree of grinding. The degree of food bolus aggregation had a sensitivity of 45.0% and specificity of 90.6%, and aspiration had a sensitivity of 25.0% and specificity of 84.5%, both of which showed high specificity. CONCLUSIONS: The results of this study suggested that the SST might be simple and useful for identifying patients with dysphagia who are able to masticate, even if they do not eat foods that need chewing and could be used before starting these patients on foods that need chewing.


Assuntos
Transtornos de Deglutição/fisiopatologia , Mastigação , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Deglutição/fisiologia , Feminino , Humanos , Masculino , Mastigação/fisiologia , Reprodutibilidade dos Testes
18.
Nature ; 550(7676): 371-374, 2017 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-29052625

RESUMO

Precise comparisons of the fundamental properties of matter-antimatter conjugates provide sensitive tests of charge-parity-time (CPT) invariance, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons, leptons and baryons have compared different properties of matter-antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron. Here we report a high-precision measurement of in units of the nuclear magneton µN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result = -2.7928473441(42)µN (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement by a factor of approximately 350. The measured value is consistent with the proton magnetic moment, µp = 2.792847350(9)µN, and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects to below 1.8 × 10-24 gigaelectronvolts, and a possible splitting of the proton-antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10-12 Bohr magnetons.

20.
Adv Exp Med Biol ; 977: 233-240, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28685451

RESUMO

Our previous studies have shown that water immersion (WI) changes sensorimotor processing and cortical excitability in the sensorimotor regions of the brain. The present study examined the site specificity of the brain activation during WI using functional near infrared spectroscopy (fNIRS). Cortical oxyhaemoglobin (O2Hb) levels in the anterior and posterior parts of the supplementary motor area (pre-SMA and SMA), primary motor cortex (M1), primary somatosensory cortex (S1), and posterior parietal cortex (PPC) were recorded using fNIRS (OMM-3000; Shimadzu Co.) before, during, and after WI in nine healthy participants. The cortical O2Hb levels in SMA, M1, S1, and PPC significantly increased during the WI and increased gradually along with the filling of the WI tank. These changes were not seen in the pre-SMA. The results show that WI-induced increases in cortical O2Hb levels are at least somewhat site specific: there was little brain activation in response to somatosensory input in the pre-SMA, but robust activation in other areas.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/metabolismo , Imersão , Oxiemoglobinas/metabolismo , Adulto , Química Encefálica , Mapeamento Encefálico/métodos , Córtex Cerebral/química , Humanos , Masculino , Córtex Motor/química , Córtex Motor/metabolismo , Especificidade de Órgãos , Oxiemoglobinas/análise , Córtex Somatossensorial/química , Córtex Somatossensorial/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Água , Adulto Jovem
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