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1.
Phys Rev Lett ; 127(21): 211801, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34860075

RESUMO

We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72 fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst) fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst) fs, are the most precise to date and are consistent with previous determinations.

2.
Phys Rev Lett ; 127(17): 171801, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34739288

RESUMO

Using a dataset of 6.32 fb^{-1} of e^{+}e^{-} annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}, and find B_{D_{s}^{+}→τ^{+}ν_{τ}}=(5.27±0.10±0.12)×10^{-2}, where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with f_{D_{s}^{+}} from lattice quantum chromodynamics calculations or the |V_{cs}| from the CKMfitter group, we extract |V_{cs}|=0.978±0.009±0.012 and f_{D_{s}^{+}}=(251.1±2.4±3.0) MeV, respectively. Combining our result with the world averages of B_{D_{s}^{+}→τ^{+}ν_{τ}} and B_{D_{s}^{+}→µ^{+}ν_{µ}}, we obtain the ratio of the branching fractions B_{D_{s}^{+}→τ^{+}ν_{τ}}/B_{D_{s}^{+}→µ^{+}ν_{µ}}=9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality.

3.
Phys Rev Lett ; 127(18): 181802, 2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34767404

RESUMO

A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63 fb^{-1} collected at the ϒ(4S) resonance and a sample of 9 fb^{-1} collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B^{+}→K^{+}νν[over ¯] decay, but also the inclusive properties of the other B meson in the ϒ(4S)→BB[over ¯] event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B^{+}→K^{+}νν[over ¯] of 4.1×10^{-5} is set at the 90% confidence level.

4.
Phys Rev Lett ; 127(12): 121802, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34597097

RESUMO

The absolute branching fraction of Λ→pµ^{-}ν[over ¯]_{µ} is reported for the first time based on an e^{+}e^{-} annihilation sample of 10×10^{9} J/ψ events collected with the BESIII detector at sqrt[s]=3.097 GeV. The branching fraction is determined to be B(Λ→pµ^{-}ν[over ¯]_{µ})=[1.48±0.21(stat)±0.08(syst)]×10^{-4}, which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of B(Λ→pe^{-}ν[over ¯]_{e}), we obtain the ratio {[Γ(Λ→pµ^{-}ν[over ¯]_{µ})]/[Γ(Λ→pe^{-}ν[over ¯]_{e})]} to be 0.178±0.028, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions of Λ→pµ^{-}ν[over ¯]_{µ} and Λ[over ¯]→p[over ¯]µ^{+}ν_{µ} is also determined, and no evidence for CP violation is found.

5.
Phys Rev Lett ; 127(13): 131801, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34623854

RESUMO

Using 2.93 fb^{-1} of e^{+}e^{-} collision data taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, the observation of the D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} semileptonic decay is presented. The statistical significance of the decay D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is greater than 10σ. The branching fraction of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is measured to be (1.09±0.13_{-0.16}^{+0.09}±0.12)×10^{-3}. Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of K_{1}(1270)^{-}→K^{-}π^{+}π^{-}. The fraction of longitudinal polarization in D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is determined for the first time to be 0.50±0.19_{stat}±0.08_{syst}.

6.
Phys Rev Lett ; 127(8): 082002, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477419

RESUMO

We report a measurement of the observed cross sections of e^{+}e^{-}→J/ψX based on 3.21 fb^{-1} of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. In analysis of the cross sections, we measured the decay branching fractions of B(ψ(3686)→J/ψX)=(64.4±0.6±1.6)% and B(ψ(3770)→J/ψX)=(0.5±0.2±0.1)% for the first time. The energy-dependent line shape of these cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays ψ(3686)→J/ψX and ψ(3770)→J/ψX. Instead, it can be better described with one more BW amplitude of the decay R(3760)→J/ψX. Under this assumption, we extracted the R(3760) mass M_{R(3760)}=3766.2±3.8±0.4 MeV/c^{2} , total width Γ_{R(3760)}^{tot}=22.2±5.9±1.4 MeV, and product of leptonic width and decay branching fraction Γ_{R(3760)}^{ee}B[R(3760)→J/ψX]=(79.4±85.5±11.7) eV. The significance of the R(3760) is 5.3σ. The first uncertainties of these measured quantities are from fits to the cross sections and second systematic.

8.
Platelets ; : 1-11, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34275420

RESUMO

Glanzmann thrombasthenia (GT) is a rare autosomal recessive bleeding disorder characterized by impaired platelet aggregation due to defects in integrin αIIbß3, a fibrinogen receptor. Platelet phenotypes and allelic variations in 28 Turkish GT patients are reported. Platelets αIIbß3 expression was evaluated by flow cytometry. Sequence analyzes of ITGA2B and ITGB3 genes allowed identifying nine variants. Non-sense variation effect on αIIbß3 expression was studied by using transfected cell lines. 3D molecular dynamics (MDs) simulations allowed characterizing structural alterations. Five new alleles were described. αIIb:p.Gly423Asp, p.Asp560Ala and p.Tyr784Cys substitutions impaired αIIbß3 expression. The αIIb:p.Gly128Val substitution allowed normal expression; however, the corresponding NM_000419.3:c.476G>T variation would create a cryptic donor splicing site altering mRNA processing. The ß3:p.Gly540Asp substitution allowed αIIbß3 expression in HEK-293 cells but induced its constitutive activation likely by impairing αIIb and ß3 legs interaction. The substitution alters the ß3 I-EGF-3 domain flexibility as shown by MDs simulations. GT variations are mostly unique although the NM_000419.3:c.1752 + 2 T > C and NM_000212.2:c.1697 G > A variations identified in 4 and 8 families, respectively, might be a current cause of GT in Turkey. MD simulations suggested how some subtle structural variations in the ß3 I-EGF domains might induce constitutive activation of αIIbß3 without altering the global domain structure.

9.
ESMO Open ; 6(3): 100165, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34052554

RESUMO

BACKGROUND: Italy was among the first countries hit by the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The application of strict lockdown measures disproportionately affected both cancer patient care as well as basic and translational cancer research. MATERIALS AND METHODS: The Italian Cancer Society (SIC) conducted a survey on the effect of lockdown on laboratories involved in cancer research in Italy. The survey was completed by 570 researchers at different stages of their career, working in cancer centers, research institutes and universities from 19 Italian regions. RESULTS: During the lockdown period, the impact of the COVID-19 pandemic emergency on face-to-face research activities was high, with a complete (47.7%) or partial (36.1%) shutdown of the laboratories. In the post-lockdown period, research activities were resumed in most of the respondents' institutions (80.4%), though with some restrictions (77.2%). COVID-19 testing was offered to research personnel only in ~50% of research institutions. Overall, the response to the pandemic was fragmented as in many cases institutions adopted different strategies often aimed at limiting possible infections without a clearly defined contingency plan. Nevertheless, research was able to provide the first answers and possible ways out of the pandemic, also with the contribution of many cancer researchers that sacrificed their research programs to help overcome the pandemic by offering their knowledge and technologies. CONCLUSIONS: Given the current persistence of an emergency situation in many European countries, a more adequate organization of research centers will be urgent and necessary to ensure the continuity of laboratory activities in a safe environment.


Assuntos
COVID-19 , Neoplasias , Adulto , Teste para COVID-19 , Controle de Doenças Transmissíveis , Europa (Continente) , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Pandemias , Pesquisa , SARS-CoV-2 , Inquéritos e Questionários , Adulto Jovem
10.
Phys Rev Lett ; 126(9): 092002, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33750166

RESUMO

We present an analysis of the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} (Ω^{-}→K^{-}Λ, Ω[over ¯]^{+}→K^{+}Λ[over ¯], Λ→pπ^{-}, Λ[over ¯]→p[over ¯]π^{+}) based on a dataset of 448×10^{6} ψ(3686) decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} and the decay parameters of the subsequent decay Ω^{-}→K^{-}Λ (Ω[over ¯]^{+}→K^{+}Λ[over ¯]) are measured for the first time by a fit to the angular distribution of the complete decay chain, and the spin of the Ω^{-} is determined to be 3/2 for the first time since its discovery more than 50 years ago.

11.
J Dairy Sci ; 104(4): 4929-4935, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33663827

RESUMO

This study estimates the accuracy of the focused lung ultrasound (FLUS) compared with systematic thoracic ultrasonography (TUS) as the reference test for diagnosing pneumonia in pre- and postweaned dairy calves. One hundred thirty-five Holstein Friesian calves, aged between 1 to 6 mo were enrolled and were kept in the same pen with one or more animals showing signs of bovine respiratory disease complex (BRDC). One operator performed FLUS on each calf, and then a second, blinded operator performed TUS on the same calf. For the FLUS, we only scanned the lung lobes that are most frequently affected during BRDC and are thus easier to detect, such as the caudal aspect of the cranial lobe of the left lung (fifth and fourth left intercostal spaces; ICS), the middle lobe of the right lung (fifth right ICS), and the caudal aspect of the cranial lobe of the right lung (fourth right ICS). Pneumonia was diagnosed when a calf had a minimum of one small lobular lung lesion that was at least 1 cm deep within a normally aerated lobe (TUS score of ≥2). Diagnostic accuracy indexes of the FLUS were calculated using TUS as the gold standard. The McNemar test was performed to evaluate the differences between the 2 techniques. In addition, an intertest agreement was assessed using the weighted kappa test. A total of 76 out of 135 calves had a TUS score of ≥2 and were therefore considered to be affected by BRDC. The FLUS had a sensitivity of 81.6% (95% CI = 71.0-89.5%), specificity = 100% (95% CI = 93.9-100%), positive predictive value was 100%, negative predictive value was 96.6% (95% CI = 94.7---97.9%), and accuracy was 97% (95% CI = 92.6-99.2%). The McNemar test highlighted a difference of 10.3% between the FLUS and TUS. The agreement between the TUS and FLUS was substantial (weighted kappa test 0.78). Although FLUS shows some limitations in diagnosing lung lesions associated with BRDC compared with the systematic approach, this study shows that the focused method could be used as an additional tool for evaluating consolidation, especially when examining a large number of postweaned dairy calves.


Assuntos
Complexo Respiratório Bovino , Pneumopatias , Doenças Respiratórias , Animais , Bovinos , Pulmão/diagnóstico por imagem , Pneumopatias/diagnóstico por imagem , Pneumopatias/veterinária , Doenças Respiratórias/veterinária , Ultrassonografia/veterinária
12.
Phys Rev Lett ; 126(10): 102001, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33784133

RESUMO

We report a study of the processes of e^{+}e^{-}→K^{+}D_{s}^{-}D^{*0} and K^{+}D_{s}^{*-}D^{0} based on e^{+}e^{-} annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7 fb^{-1}. An excess of events over the known contributions of the conventional charmed mesons is observed near the D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0} mass thresholds in the K^{+} recoil-mass spectrum for events collected at sqrt[s]=4.681 GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5_{-2.6}^{+1.8}±2.1) MeV/c^{2} and (12.8_{-4.4}^{+5.3}±3.0) MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3 σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0}. However, the properties of the excess need further exploration with more statistics.

13.
Ann Ig ; 33(2): 201-202, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33570091

RESUMO

the SARS-CoV-2 pandemic started in December 2019 and still remains a major global health issue. Every country in the world has adopted drastic measures to contain the virus, although their stringency varies among countries, ranging from increased surveillance and focused interventions to strict lockdown (1). Italy was the second country where the disease had a major impact early in the pandemic, such that a strict nationwide lockdown was declared from March 9 to May 3, 2020. Nonetheless, between January and May 2020, there were 210,000 COVID-19 cases in Italy and 29,000 deaths were recorded (2). Due to the lockdown, universities (and in general all educational services) shifted to online classes, with students attending lessons and taking their exams from home. On-site activities were reduced to those considered indispensable. Research activities also had to be modified, such as by the adoption of a smart-working model (3). Between May and August 2020, the number of SARS-CoV-2 infections in Italy decreased. In response, the lockdown was loosened and some activities were restarted, albeit with specific safety protocols (social distancing, use of masks, temperature checks at the workplace entry, environmental disinfection, mixed models of smart and in-office work). These actions were accompanied by periodic serological and PCR screening tests (4).


Assuntos
COVID-19/prevenção & controle , Pandemias , SARS-CoV-2 , Universidades , COVID-19/epidemiologia , Controle de Doenças Transmissíveis/métodos , Humanos , Itália/epidemiologia , Máscaras , Distanciamento Físico , Vacinação
15.
Sci Total Environ ; 769: 144703, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33486188

RESUMO

Thyroid hormones (THs) are major regulators of biological processes essential for correct development and energy homeostasis. Although thyroid disruptors can deeply affect human health, the impact of exogenous chemicals and in particular mixture of chemicals on different aspects of thyroid development and metabolism is not yet fully understood. In this study we have used the highly versatile zebrafish model to assess the thyroid axis disrupting effects of cadmium (Cd) and dibenzothiophene (DBT), two environmental endocrine disruptors found to be significantly correlated in epidemiological co-exposure studies. Zebrafish embryos (5hpf) were exposed to low concentrations of Cd (from 0.05 to 2 µM) and DBT (from 0.05 to 1 µM) and to mixtures of them. A multilevel assessment of the pollutant effects has been obtained by combining in vivo morphological analyses allowed by the use of transgenic fluorescent lines with liquid chromatography mass spectrometry determination of TH levels and quantification of the expression levels of key genes involved in the Hypothalamic-Pituitary-Thyroid Axis (HPTA) and TH metabolism. Our results underscore for the first time an important synergistic toxic effect of these pollutants on embryonic development and thyroid morphology highlighting differences in the mechanisms through which they can adversely impact on multiple physiological processes of the HPTA and TH disposal influencing also heart geometry and function.


Assuntos
Disruptores Endócrinos , Poluentes Químicos da Água , Animais , Cádmio/toxicidade , Humanos , Tiofenos , Glândula Tireoide , Hormônios Tireóideos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
16.
Talanta ; 224: 121891, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379099

RESUMO

The occurrence of emerging contaminants is becoming of increasing importance to assess the impact of anthropogenic activities onto the environment. The present study reports for the first time the development and validation of an efficient method for the simultaneous determination of fragrance materials in water samples based on the use of a novel multiwalled carbon nanotubes (MWCNTs)-based solid-phase microextraction coating. Helical MWCNTs were selected as adsorbent material due to their outstanding extraction performance. The multicriteria method of desirability functions allowed the optimization of the experimental conditions in terms of extraction time and extraction temperature. Validation proved the reliability of the method for the determination of the analytes at ultra-trace levels, obtaining detection limits in the 0.2-13 ng/L range, good precision, with relative standard deviations lower than 20% and recovery rates in the 80 ± 12%-111 ± 11%. Superior enrichment factors compared to commercial fibers were also calculated. Finally, applicability to real sample analysis was demonstrated.

18.
Phys Rev Lett ; 125(16): 161806, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33124872

RESUMO

We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e^{+}e^{-}→γa, a→γγ in the mass range 0.2

19.
Phys Rev Lett ; 125(14): 141802, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064551

RESUMO

Using 2.93 fb^{-1} of e^{+}e^{-} collision data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the first observation of the doubly Cabibbo-suppressed decay D^{+}→K^{+}π^{+}π^{-}π^{0} is reported. After removing decays that contain narrow intermediate resonances, including D^{+}→K^{+}η, D^{+}→K^{+}ω, and D^{+}→K^{+}ϕ, the branching fraction of the decay D^{+}→K^{+}π^{+}π^{-}π^{0} is measured to be (1.13±0.08_{stat}±0.03_{syst})×10^{-3}. The ratio of branching fractions of D^{+}→K^{+}π^{+}π^{-}π^{0} over D^{+}→K^{-}π^{+}π^{+}π^{0} is found to be (1.81±0.15)%, which corresponds to (6.28±0.52)tan^{4}θ_{C}, where θ_{C} is the Cabibbo mixing angle. This ratio is significantly larger than the corresponding ratios for other doubly Cabibbo-suppressed decays. The asymmetry of the branching fractions of charge-conjugated decays D^{±}→K^{±}π^{±}π^{∓}π^{0} is also determined, and no evidence for CP violation is found. In addition, the first evidence for the D^{+}→K^{+}ω decay, with a statistical significance of 3.3σ, is presented and the branching fraction is measured to be B(D^{+}→K^{+}ω)=(5.7_{-2.1}^{+2.5}_{stat}±0.2_{syst})×10^{-5}.

20.
Br J Neurosurg ; : 1-3, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33000956

RESUMO

The space existing between the external and internal dural layer has been anatomically described as a virtual space; no clear clinical significance has been given to it to date. We hereby describe a case of a child with what was expected to be a purely epidural hematoma, at surgery, was found to be composed of two equally coexistent components, one in the epidural space and the second one between the two dural layers. The recognition of a possible involvement of the transdural space in the case of post-traumatic epidural hematomas is relevant for a correct conclusion of the surgical treatment of epidural hematomas, extensively considered basic practice among neurosurgical procedures.

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