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1.
Phys Rev Lett ; 131(20): 201801, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-38039482

RESUMO

A new dark sector antibaryon, denoted ψ_{D}, could be produced in decays of B mesons. This Letter presents a search for B^{+}→ψ_{D}+p (and the charge conjugate) decays in e^{+}e^{-} annihilations at 10.58 GeV, using data collected in the BABAR experiment. Data corresponding to an integrated luminosity of 398 fb^{-1} are analyzed. No evidence for a signal is observed. Branching fraction upper limits in the range from 10^{-7}-10^{-5} are obtained at 90% confidence level for masses of 1.0

2.
Environ Res ; 233: 116330, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37348639

RESUMO

BACKGROUND: Epidemiological studies have reported associations of anti-androgenic phthalate metabolite concentrations with later onset of male puberty, but few have assessed associations with progression. OBJECTIVES: We examined the association of prepubertal urinary phthalate metabolite concentrations with trajectories of pubertal progression among Russian boys. METHODS: At enrollment (ages 8-9 years), medical history, dietary, and demographic information were collected. At entry and annually to age 19 years, physical examinations including testicular volume (TV) were performed and spot urines collected. Each boy's prepubertal urine samples were pooled, and 15 phthalate metabolites were quantified by isotope dilution LC-MS/MS at Moscow State University. Metabolites of anti-androgenic parent phthalates were included: butylbenzyl (BBzP), di-n-butyl (DnBP), diisobutyl (DiBP), di(2-ethylhexyl) (DEHP) and diisononyl (DiNP) phthalates. We calculated the molar sums of DEHP, DiNP, and all AAP metabolites. We used group-based trajectory models (GBTMs) to identify subgroups of boys who followed similar pubertal trajectories from ages 8-19 years based on annual TV. We used multinomial and ordinal regression models to evaluate whether prepubertal log-transformed phthalate metabolite concentrations were associated with slower or faster pubertal progression trajectories, adjusting for covariates. RESULTS: 304 boys contributed a total of 752 prepubertal urine samples (median 2, range: 1-6) for creation of individual pools. The median length of follow-up was 10.0 years; 79% of boys were followed beyond age 15. We identified three pubertal progression groups: slower (34%), moderate (43%), and faster (23%) progression. A standard deviation increase in urinary log-monobenzyl phthalate (MBzP) concentrations was associated with higher adjusted odds of being in the slow versus faster pubertal progression trajectory (aOR 1.47, 95% CI 1.06-2.04). None of the other phthalate metabolites were associated with pubertal progression. CONCLUSIONS: On average, boys with higher concentrations of prepubertal urinary MBzP had a slower tempo of pubertal progression, perhaps attributable to the disruption of androgen-dependent biological pathways.


Assuntos
Dietilexilftalato , Poluentes Ambientais , Ácidos Ftálicos , Humanos , Masculino , Adulto Jovem , Adulto , Adolescente , Poluentes Ambientais/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Ácidos Ftálicos/urina , Antagonistas de Androgênios , Exposição Ambiental/análise
3.
Phys Rev Lett ; 128(13): 131802, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35426701

RESUMO

Axionlike particles (ALPs) are predicted in many extensions of the standard model, and their masses can naturally be well below the electroweak scale. In the presence of couplings to electroweak bosons, these particles could be emitted in flavor-changing B meson decays. We report herein a search for an ALP, a, in the reaction B^{±}→K^{±}a, a→γγ using data collected by the BABAR experiment at SLAC. No significant signal is observed, and 90% confidence level upper limits on the ALP coupling to electroweak bosons are derived as a function of ALP mass, improving current constraints by several orders of magnitude in the range 0.175 GeV

4.
Phys Rev Lett ; 128(2): 021802, 2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35089770

RESUMO

Collider searches for dark sectors, new particles interacting only feebly with ordinary matter, have largely focused on identifying signatures of new mediators, leaving much of dark sector structures unexplored. In particular, the existence of dark matter bound states (darkonia) remains to be investigated. This possibility could arise in a simple model in which a dark photon (A^{'}) is light enough to generate an attractive force between dark fermions. We report herein a search for a J^{PC}=1^{--} darkonium state, the ϒ_{D}, produced in the reaction e^{+}e^{-}→γϒ_{D}, ϒ_{D}→A^{'}A^{'}A^{'}, where the dark photons subsequently decay into pairs of leptons or pions, using 514 fb^{-1} of data collected with the BABAR detector. No significant signal is observed, and we set bounds on the γ-A^{'} kinetic mixing as a function of the dark sector coupling constant for 0.001

5.
Phys Rev Lett ; 128(9): 091804, 2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35302790

RESUMO

We report on the first search for electron-muon lepton flavor violation (LFV) in the decay of a b quark and b antiquark bound state. We look for the LFV decay ϒ(3S)→e^{±}µ^{∓} in a sample of 118 million ϒ(3S) mesons from 27 fb^{-1} of data collected with the BABAR detector at the SLAC PEP-II e^{+}e^{-} collider operating with a 10.36 GeV center-of-mass energy. No evidence for a signal is found, and we set a limit on the branching fraction B[ϒ(3S)→e^{±}µ^{∓}]<3.6×10^{-7} at 90% C. L. This result can be interpreted as a limit Λ_{NP}/g_{NP}^{2}>80 TeV on the energy scale Λ_{NP} divided by the coupling-squared g_{NP}^{2} of relevant new physics (NP).

6.
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.

7.
Phys Rev Lett ; 125(24): 241801, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33412062

RESUMO

We report on a precision measurement of the ratio R_{τµ}^{ϒ(3S)}=B(ϒ(3S)→τ^{+}τ^{-})/B(ϒ(3S)→µ^{+}µ^{-}) using data collected with the BABAR detector at the SLAC PEP-II e^{+}e^{-} collider. The measurement is based on a 28 fb^{-1} data sample collected at a center-of-mass energy of 10.355 GeV corresponding to a sample of 122 million ϒ(3S) mesons. The ratio is measured to be R_{τµ}^{ϒ(3S)}=0.966±0.008_{stat}±0.014_{syst} and is in agreement with the standard model prediction of 0.9948 within 2 standard deviations. The uncertainty in R_{τµ}^{ϒ(3S)} is almost an order of magnitude smaller than the only previous measurement.

8.
Phys Rev Lett ; 125(18): 181801, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33196250

RESUMO

Many scenarios of physics beyond the standard model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional scalars with masses in the MeV to GeV range could be significantly weakened if they interact predominantly with leptons rather than quarks. At an e^{+}e^{-} collider, such a leptophilic scalar (ϕ_{L}) would be produced predominantly through radiation from a τ lepton. We report herein a search for e^{+}e^{-}→τ^{+}τ^{-}ϕ_{L}, ϕ_{L}→ℓ^{+}ℓ^{-} (ℓ=e, µ) using data collected by the BABAR experiment at SLAC. No significant signal is observed, and we set limits on the ϕ_{L} coupling to leptons in the range 0.04

9.
Phys Rev Lett ; 124(7): 071802, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32142319

RESUMO

We present a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type D^{0}→h^{'-}h^{-}ℓ^{'+}ℓ^{+} and D^{0}→h^{'-}h^{+}ℓ^{'±}ℓ^{∓}, where h and h^{'} represent a K or π meson and ℓ and ℓ^{'} an electron or muon. The analysis is based on 468 fb^{-1} of e^{+}e^{-} annihilation data collected at or close to the ϒ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the twelve modes, and we establish 90% confidence level upper limits on the branching fractions in the range (1.0-30.6)×10^{-7}. The limits are between 1 and 3 orders of magnitude more stringent than previous measurements.

10.
Phys Rev Lett ; 124(15): 152001, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32357020

RESUMO

A study of the two-body decays B^{±}→X_{cc[over ¯]}K^{±}, where X_{cc[over ¯]} refers to one charmonium state, is reported by the BABAR Collaboration using a data sample of 424 fb^{-1}. The absolute determination of branching fractions for these decays are significantly improved compared to previous BABAR measurements. Evidence is found for the decay B^{+}→X(3872)K^{+} at the 3σ level. The absolute branching fraction B[B^{+}→X(3872)K^{+}]=[2.1±0.6(stat)±0.3(syst)]×10^{-4} is measured for the first time. It follows that B[X(3872)→J/ψπ^{+}π^{-}]=(4.1±1.3)%, supporting the hypothesis of a molecular component for this resonance.

11.
Int Nurs Rev ; 67(4): 476-483, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32767464

RESUMO

AIM: The purpose of this research was to determine the effectiveness of a mobile health or mHealth application to improve hypertension health literacy among vulnerable populations in India. Additionally, we sought to estimate relationships between participant knowledge on hypertension and sociodemographic variables. BACKGROUND: The World Health Organization advocates for the use of mobile technology to improve public health outcomes. INTRODUCTION: The incidence of hypertension is on the rise in India, and effective and sustainable interventions are needed. METHODS: A quantitative single arm pre-test post-test interventional and correlational design was used to test the hypertension mHealth application among participants in a limited resource setting. A paired t-test was performed to compare pre- and post-test results after participant use of the mHealth application. A regression model was used to estimate relationships between participant hypertension health literacy and sociodemographic variables. RESULTS: A statistically significant improvement in test scores among participants after use of the mHealth app was found. Sociodemographic characteristics such as living in an urban environment, married, increased number of people living in household and alcohol use were determined to have a statistically significant effect on improvement of test score. DISCUSSION: Results indicated the application was effective among participants with varied literacy and health literacy levels. These findings contribute to the potential widespread scalability of the app among populations with varied demographics. CONCLUSION: This application provides an effective and valuable culturally tailored educational resource for nurses and other health providers to use to improve hypertension health literacy among vulnerable populations in India. IMPLICATIONS FOR NURSING PRACTICE AND HEALTH POLICY: This study contributes to nursing and health policy by answering a call from the World Health Organization to implement and research mHealth interventions to improve health outcomes, particularly in a low and middle income country where preventive health access is limited.


Assuntos
Letramento em Saúde , Hipertensão , Telemedicina , Humanos , Hipertensão/prevenção & controle , Índia
12.
J Cell Biochem ; 120(1): 396-404, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30126049

RESUMO

Coculturing of bone-forming and blood vessel-forming cells is a strategy aimed at increasing vascularity of implanted bone constructs in tissue-engineering applications. We previously described that the coculture of primary human osteoblasts (hOBs) and human umbilical vein endothelial cells (HUVECs) improves the differentiation of both cell types, leading to the formation of functional blood vessels and enhanced bone regeneration. The objective of this study was to further delineate the multifaceted interactions between both cell types. To investigate the proteome of hOBs after cocultivation with HUVECs we used stable isotope labeling by amino acids in cell culture, revealing 49 significantly upregulated, and 54 significantly downregulated proteins. Amongst the highest regulated proteins, we found the proteins important for osteoblast differentiation, cellular adhesion, and extracellular matrix function, notably: connective tissue growth factor, desmoplakin, galectin-3, and cyclin-dependent kinase 6. The findings were confirmed by enzyme-linked immunosorbent assays. We also investigated whether the mRNA transcripts correlate with the changes in protein levels by quantitative real-time reverse transcription polymerase chain reaction. In addition, the data was compared to our previous microarray analysis of hOB transcriptome. Taken together, this in-depth analysis delivers reliable data suggesting the importance of coculturing of hOBs and HUVECs in tissue engineering.


Assuntos
Diferenciação Celular/fisiologia , Matriz Extracelular/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Osteoblastos/metabolismo , Proteômica/métodos , Proteínas Sanguíneas , Regeneração Óssea , Células Cultivadas , Técnicas de Cocultura/métodos , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Quinase 6 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/metabolismo , Desmoplaquinas/genética , Desmoplaquinas/metabolismo , Regulação para Baixo/genética , Galectina 3/genética , Galectina 3/metabolismo , Galectinas , Humanos , Osteogênese , RNA Mensageiro/genética , Engenharia Tecidual/métodos , Transcrição Gênica , Regulação para Cima/genética
13.
Phys Rev Lett ; 123(9): 091801, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31524470

RESUMO

An angular analysis of the decay B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}, ℓ∈{e,µ}, is reported using the full e^{+}e^{-} collision data set collected by the BABAR experiment at the ϒ(4S) resonance. One B meson from the ϒ(4S)→BB[over ¯] decay is fully reconstructed in a hadronic decay mode, which constrains the kinematics and provides a determination of the neutrino momentum vector. The kinematics of the semileptonic decay is described by the dilepton mass squared, q^{2}, and three angles. The first unbinned fit to the full four-dimensional decay rate in the standard model is performed in the so-called Boyd-Grinstein-Lebed approach, which employs a generic q^{2} parametrization of the underlying form factors based on crossing symmetry, analyticity, and QCD dispersion relations for the amplitudes. A fit using the more model-dependent Caprini-Lellouch-Neubert (CLN) approach is performed as well. Our form factor shapes show deviations from previous fits based on the CLN parametrization. The latest form factors also provide an updated prediction for the branching fraction ratio R(D^{*})≡B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ})=0.253±0.005. Finally, using the well-measured branching fraction for the B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ} decay, a value of |V_{cb}|=(38.36±0.90)×10^{-3} is obtained that is consistent with the current world average for exclusive B[over ¯]→D^{(*)}ℓ^{-}ν[over ¯]_{ℓ} decays and remains in tension with the determination from inclusive semileptonic B decays to final states with charm.

14.
Phys Rev Lett ; 122(8): 081802, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30932586

RESUMO

We report the observation of the rare charm decay D^{0}→K^{-}π^{+}e^{+}e^{-}, based on 468 fb^{-1} of e^{+}e^{-} annihilation data collected at or close to the center-of-mass energy of the ϒ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. We find the branching fraction in the invariant mass range 0.675

15.
Phys Rev Lett ; 122(7): 072002, 2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30848619

RESUMO

Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate. We report the first search for a stable, doubly strange six-quark state in ϒ→SΛ[over ¯]Λ[over ¯] decays based on a sample of 90×10^{6}ϒ(2S) and 110×10^{6}ϒ(3S) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined ϒ(2S,3S)→SΛ[over ¯]Λ[over ¯] branching fraction in the range (1.2-1.4)×10^{-7} are derived for m_{S}<2.05 GeV. These bounds set stringent limits on the existence of such exotic particles.

16.
Indoor Air ; 28(2): 247-257, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29095533

RESUMO

This study aims to elucidate in greater detail the dermal uptake of nicotine from air or from nicotine-exposed clothes, which was demonstrated recently in a preliminary study. Six non-smoking participants were exposed to gaseous nicotine (between 236 and 304 µg/m3 ) over 5 hours while breathing clean air through a hood. Four of the participants wore only shorts and 2 wore a set of clean clothes. One week later, 2 of the bare-skinned participants were again exposed in the chamber, but they showered immediately after exposure instead of the following morning. The 2 participants who wore clean clothes on week 1 were now exposed wearing a set of clothes that had been exposed to nicotine. All urine was collected for 84 hours after exposure and analyzed for nicotine and its metabolites, cotinine and 3OH-cotinine. All participants except those wearing fresh clothes excreted substantial amounts of biomarkers, comparable to levels expected from inhalation intake. Uptake for 1 participant wearing exposed clothes exceeded estimated intake via inhalation by >50%. Biomarker excretion continued during the entire urine collection period, indicating that nicotine accumulates in the skin and is released over several days. Absorbed nicotine was significantly lower after showering in 1 subject but not the other. Differences in the normalized uptakes and in the excretion patterns were observed among the participants. The observed cotinine half-lives suggest that non-smokers exposed to airborne nicotine may receive a substantial fraction through the dermal pathway. Washing skin and clothes exposed to nicotine may meaningfully decrease exposure.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Vestuário , Exposição Ambiental/análise , Nicotina/análise , Poluição por Fumaça de Tabaco/análise , Idoso , Monitoramento Ambiental/métodos , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Nicotina/farmacocinética , Pele/metabolismo , Absorção Cutânea
17.
Phys Rev Lett ; 118(3): 031802, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-28157371

RESUMO

We search for the rare flavor-changing neutral current process B^{+}→K^{+}τ^{+}τ^{-} using data from the BABAR experiment. The data sample, collected at the center-of-mass energy of the ϒ(4S) resonance, corresponds to a total integrated luminosity of 424 fb^{-1} and to 471×10^{6} BB[over ¯] pairs. We reconstruct one B meson, produced in the ϒ(4S)→B^{+}B^{-} decay, in one of many hadronic decay modes and search for activity compatible with a B^{+}→K^{+}τ^{+}τ^{-} decay in the rest of the event. Each τ lepton is required to decay leptonically into an electron or muon and neutrinos. Comparing the expected number of background events with the data sample after applying the selection criteria, we do not find evidence for a signal. The resulting upper limit, at the 90% confidence level, is B(B^{+}→K^{+}τ^{+}τ^{-})<2.25×10^{-3}.

18.
Phys Rev Lett ; 119(13): 131804, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-29341718

RESUMO

We search for single-photon events in 53 fb^{-1} of e^{+}e^{-} collision data collected with the BABAR detector at the PEP-II B-Factory. We look for events with a single high-energy photon and a large missing momentum and energy, consistent with production of a spin-1 particle A^{'} through the process e^{+}e^{-}→γA^{'}; A^{'}→invisible. Such particles, referred to as "dark photons," are motivated by theories applying a U(1) gauge symmetry to dark matter. We find no evidence for such processes and set 90% confidence level upper limits on the coupling strength of A^{'} to e^{+}e^{-} in the mass range m_{A^{'}}≤8 GeV. In particular, our limits exclude the values of the A^{'} coupling suggested by the dark-photon interpretation of the muon (g-2)_{µ} anomaly, as well as a broad range of parameters for the dark-sector models.

19.
Phys Rev Lett ; 119(20): 202003, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-29219353

RESUMO

We measure the mass difference, Δm_{+}, between the D^{*}(2010)^{+} and the D^{+} using the decay chain D^{*}(2010)^{+}→D^{+}π^{0} with D^{+}→K^{-}π^{+}π^{+}. The data were recorded with the BABAR detector at center-of-mass energies at and near the ϒ(4S) resonance, and correspond to an integrated luminosity of approximately 468 fb^{-1}. We measure Δm_{+}=(140 601.0±6.8[stat]±12.9[syst]) keV. We combine this result with a previous BABAR measurement of Δm_{0}≡m(D^{*}(2010)^{+})-m(D^{0}) to obtain Δm_{D}=m(D^{+})-m(D^{0})=(4824.9±6.8[stat]±12.9[syst]) keV. These results are compatible with and approximately five times more precise than the Particle Data Group averages.

20.
J Evol Biol ; 30(1): 210-220, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27717228

RESUMO

A species reproductive mode, along with its associated costs and benefits, can play a significant role in its evolution and survival. Facultative sexuality, being able to reproduce both sexually and asexually, has been deemed evolutionary favourable as the benefits of either mode may be fully realized. In fact, many studies have focused on identifying the benefits of sex and/or the forces selecting for increased rates of sex using facultative sexual species. The costs of either mode, however, can also have a profound impact on a population's evolutionary trajectory. Here, we used experimental evolution and fitness assays to investigate the consequences of facultative sexuality in prey adapting to predation. Specifically, we compared the adaptive response of algal prey populations exposed to constant rotifer predation and which had alternating cycles of asexual and sexual reproduction where sexual episodes were either facultative (sexual and asexual progeny simultaneously propagated) or obligate (only sexual progeny propagated). We found that prey populations with facultative sexual episodes reached a lower final relative fitness and suffered a greater trade-off in traits under selection, that is defence and competitive ability, as compared to prey populations with obligate sexual episodes. Our results suggest that costs associated with sexual reproduction (germination time) and asexual reproduction (selection interference) were amplified in the facultative sexual prey populations, leading to a reduction in the net advantage of sexuality. Additionally, we found evidence that the cost of sex was reduced in the obligate sexual prey populations because increased selection for sex was observed via the spontaneous production of sexual cells. These results show that certain costs associated with facultative sexuality can affect an organism's evolutionary trajectory.


Assuntos
Evolução Biológica , Comportamento Predatório , Reprodução , Rotíferos , Adaptação Fisiológica , Animais , Reprodução Assexuada
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