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1.
Phys Rev Lett ; 122(10): 101101, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30932626

RESUMO

Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1×10^{6} electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux exhibits a significant excess starting from 42.1_{-5.2}^{+5.4} GeV compared to the lower energy trends, but the nature of this excess is different from the positron flux excess above 25.2±1.8 GeV. Contrary to the positron flux, which has an exponential energy cutoff of 810_{-180}^{+310} GeV, at the 5σ level the electron flux does not have an energy cutoff below 1.9 TeV. In the entire energy range the electron flux is well described by the sum of two power law components. The different behavior of the cosmic-ray electrons and positrons measured by the Alpha Magnetic Spectrometer is clear evidence that most high energy electrons originate from different sources than high energy positrons.

2.
Phys Rev Lett ; 122(4): 041102, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30768313

RESUMO

Precision measurements of cosmic ray positrons are presented up to 1 TeV based on 1.9 million positrons collected by the Alpha Magnetic Spectrometer on the International Space Station. The positron flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25.2±1.8 GeV compared to the lower-energy, power-law trend, (b) a sharp dropoff above 284_{-64}^{+91} GeV, (c) in the entire energy range the positron flux is well described by the sum of a term associated with the positrons produced in the collision of cosmic rays, which dominates at low energies, and a new source term of positrons, which dominates at high energies, and (d) a finite energy cutoff of the source term of E_{s}=810_{-180}^{+310} GeV is established with a significance of more than 4σ. These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter annihilation or from other astrophysical sources.

3.
Phys Rev Lett ; 121(5): 051101, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30118264

RESUMO

We present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of 1×10^{9} events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above ∼3 GV the p/He flux ratio is time independent. We observed that below ∼3 GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise.

4.
Phys Rev Lett ; 121(5): 051103, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30118280

RESUMO

A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×10^{6} events is presented. The detailed rigidity dependence of the nitrogen flux spectral index is presented for the first time. The spectral index rapidly hardens at high rigidities and becomes identical to the spectral indices of primary He, C, and O cosmic rays above ∼700 GV. We observed that the nitrogen flux Φ_{N} can be presented as the sum of its primary component Φ_{N}^{P} and secondary component Φ_{N}^{S}, Φ_{N}=Φ_{N}^{P}+Φ_{N}^{S}, and we found Φ_{N} is well described by the weighted sum of the oxygen flux Φ_{O} (primary cosmic rays) and the boron flux Φ_{B} (secondary cosmic rays), with Φ_{N}^{P}=(0.090±0.002)×Φ_{O} and Φ_{N}^{S}=(0.62±0.02)×Φ_{B} over the entire rigidity range. This corresponds to a change of the contribution of the secondary cosmic ray component in the nitrogen flux from 70% at a few GV to <30% above 1 TV.

5.
Phys Rev Lett ; 121(5): 051102, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30118287

RESUMO

We present high-statistics, precision measurements of the detailed time and energy dependence of the primary cosmic-ray electron flux and positron flux over 79 Bartels rotations from May 2011 to May 2017 in the energy range from 1 to 50 GeV. For the first time, the charge-sign dependent modulation during solar maximum has been investigated in detail by leptons alone. Based on 23.5×10^{6} events, we report the observation of short-term structures on the timescale of months coincident in both the electron flux and the positron flux. These structures are not visible in the e^{+}/e^{-} flux ratio. The precision measurements across the solar polarity reversal show that the ratio exhibits a smooth transition over 830±30 days from one value to another. The midpoint of the transition shows an energy dependent delay relative to the reversal and changes by 260±30 days from 1 to 6 GeV.

6.
Phys Rev Lett ; 120(2): 021101, 2018 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-29376729

RESUMO

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

7.
Phys Rev Lett ; 119(25): 251101, 2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29303302

RESUMO

We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.

8.
Phys Rev Lett ; 117(23): 231102, 2016 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-27982618

RESUMO

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.

9.
Phys Rev Lett ; 117(9): 091103, 2016 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-27610839

RESUMO

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

10.
Phys Rev Lett ; 115(21): 211101, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26636836

RESUMO

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

11.
Phys Rev Lett ; 114(17): 171103, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25978222

RESUMO

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

12.
Phys Rev Lett ; 113(22): 221102, 2014 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-25494065

RESUMO

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

13.
Phys Rev Lett ; 113(12): 121102, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25279617

RESUMO

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30 GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

14.
Phys Rev Lett ; 113(12): 121101, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25279616

RESUMO

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the positron fraction no longer exhibits an increase with energy.

15.
Phys Rev Lett ; 110(14): 141102, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-25166975

RESUMO

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250 GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

16.
Adv Ther ; 17(3): 159-66, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11183453

RESUMO

Treatment options for bacterial vaginosis (BV) include oral and topical formulations of metronidazole or topical formulations of clindamycin. Opinions of a new vaginal suppository form of clindamycin, administered for 3 days, were obtained in a survey of 96 women who had been generally satisfied with their previous treatment. Following manipulation of the clindamycin ovule and metronidazole vaginal gel, more respondents expressed a preference for the ovule (52% vs 47%), and 54% preferred the ovule to the gel (44%) for possible future use. The gel was rated easier to use, but the ovule was found to be less messy. After manipulating both products, respondents read a profile of the ovule and identified the 3-day course as its most beneficial feature, citing this reason as increasing their likelihood of completing therapy with the ovule than with the gel. Approximately three fourths of the respondents who initially preferred the gel switched their preference to the ovule after reading the product profile. At that point, 86.5% of all respondents preferred the ovule. These results suggest the potential for improved compliance with therapy for BV with the clindamycin ovule.


Assuntos
Antibacterianos/administração & dosagem , Anti-Infecciosos/administração & dosagem , Clindamicina/administração & dosagem , Metronidazol/administração & dosagem , Satisfação do Paciente , Vaginose Bacteriana/tratamento farmacológico , Administração Intravaginal , Adulto , Análise de Variância , Esquema de Medicação , Feminino , Géis , Humanos , Pessoa de Meia-Idade , Supositórios , Inquéritos e Questionários , Resultado do Tratamento
18.
Top Hosp Pharm Manage ; 14(3): 47-57, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10138928

RESUMO

Providing complete and understandable information to patients about medicines is considered an integral component of high-quality medical and pharmaceutical care. With such information, not only can the level of general health increase, but costs associated with noncompliance, including polypharmacy and hospitalization, can decrease. Although patient information leaflets (PILs) have been available since the 1970s, their use is more relevant today because of the counseling requirements of the Omnibus Budget Reconciliation Act of 1990. A national survey of community pharmacists was conducted to determine their attitudes toward this patient education strategy. Results demonstrate that pharmacists believe PILs benefit patients, but that PILs need revision in terms of readability, understandability, and standardization.


Assuntos
Atitude do Pessoal de Saúde , Serviços Comunitários de Farmácia/normas , Rotulagem de Medicamentos/normas , Educação de Pacientes como Assunto/normas , Serviços Comunitários de Farmácia/estatística & dados numéricos , Análise Custo-Benefício , Aconselhamento/normas , Aconselhamento/estatística & dados numéricos , Indústria Farmacêutica , Rotulagem de Medicamentos/economia , Estudos de Avaliação como Assunto , Necessidades e Demandas de Serviços de Saúde , Humanos , Educação de Pacientes como Assunto/estatística & dados numéricos , Farmacêuticos/psicologia , Farmacêuticos/estatística & dados numéricos , Inquéritos e Questionários , Estados Unidos
19.
Am Pharm ; NS34(8): 48-53, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7942501

RESUMO

As the popularity of self-medication and direct-to-consumer advertising of prescription drugs increases, the quality, availability, and utility of current patient information strategies become key concerns for pharmacists. It has been suggested that patient package inserts (PPIs) are a high-quality source of information for patients. To determine if this is true, 63 PPIs from three types of sources were assessed for readability and design. Suggested readability level is fifth-to-seventh grade. The PPIs studied had, on average, a 10th-grade reading level. Design characteristics, such as type size and paper quality--which affect patients' likelihood of using the PPI and keeping it for reference--were poorest in PPIs produced by pharmaceutical manufacturers. Overall, associations produce the best PPIs, with commercial vendors and pharmaceutical manufacturers following. However, both readability and design evaluations showed that all PPIs need improvement. Design and testing of new PPI formats and a reassessment of readability are recommended.


Assuntos
Rotulagem de Medicamentos/normas , Prescrições de Medicamentos , Desenho de Equipamento , Humanos , Farmacêuticos , Leitura , Automedicação
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