78 research outputs found

    Emergence of the brain-border immune niches and their contribution to the development of neurodegenerative diseases

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    Historically, the central nervous system (CNS) was regarded as ‘immune-privileged’, possessing its own distinct immune cell population. This immune privilege was thought to be established by a tight blood-brain barrier (BBB) and blood-cerebrospinal-fluid barrier (BCSFB), which prevented the crossing of peripheral immune cells and their secreted factors into the CNS parenchyma. However, recent studies have revealed the presence of peripheral immune cells in proximity to various brain-border niches such as the choroid plexus, cranial bone marrow (CBM), meninges, and perivascular spaces. Furthermore, emerging evidence suggests that peripheral immune cells may be able to infiltrate the brain through these sites and play significant roles in driving neuronal cell death and pathology progression in neurodegenerative disease. Thus, in this review, we explore how the brain-border immune niches may contribute to the pathogenesis of neurodegenerative disorders such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and multiple sclerosis (MS). We then discuss several emerging options for harnessing the neuroimmune potential of these niches to improve the prognosis and treatment of these debilitative disorders using novel insights from recent studies

    Prevalence and factors associated with rotavirus infection among children admitted with acute diarrhea in Uganda

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    <p>Abstract</p> <p>Background</p> <p>Rotavirus remains the commonest cause of severe dehydrating diarrhea among children worldwide. Children in developing countries die more because of several factors including poorer access to hydration therapy and greater prevalence of malnutrition. Hitherto, the magnitude of rotavirus disease in Uganda has remained unknown. This study was therefore done to determine the prevalence and factors associated with rotavirus infection among children aged 3-59 months admitted with acute diarrhea to paediatric emergency ward of Mulago Hospital, Uganda</p> <p>Methods</p> <p>Three hundred and ninety children, aged between 3-59 months with acute diarrhoea were recruited. The clinical history, socio-demographic characteristics, physical examination findings and laboratory investigations were recorded. Stool samples were tested for rotavirus antigens using the DAKO IDEIA rotavirus EIA detection kit.</p> <p>Results</p> <p>The prevalence of rotavirus infection was 45.4%. On multivariate analysis rotavirus was significantly associated with a higher education (above secondary) level of the mother [OR 1.8; 95% CI 1.1-2.7]; dehydration [OR 1.8; 95% CI 1.1-3.0] and breastfeeding [OR 2.6; 95% CI 1.4-4.0]. Although age was significantly associated with rotavirus on bivariate analysis; this association disappeared on multivariate analysis. No significant association was found between rotavirus infection and nutritional status, HIV status and attendance of day care or school.</p> <p>Conclusions</p> <p>Rotavirus infection is highly prevalent among children with acute diarrhoea admitted to Mulago Hospital in Uganda.</p

    Measurement of the integrated luminosity of the Phase 2 data of the Belle II experiment

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    From April to July 2018, a data sample at the peak energy of the γ(4S) resonance was collected with the Belle II detector at the SuperKEKB electron-positron collider. This is the first data sample of the Belle II experiment. Using Bhabha and digamma events, we measure the integrated luminosity of the data sample to be (496.3 ± 0.3 ± 3.0) pb-1, where the first uncertainty is statistical and the second is systematic. This work provides a basis for future luminosity measurements at Belle II

    Observation of BD()KKS0{B\to D^{(*)} K^- K^{0}_S} decays using the 2019-2022 Belle II data sample

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    We present a measurement of the branching fractions of four B0,D()+,0KKS0B^{0,-}\to D^{(*)+,0} K^- K^{0}_S decay modes. The measurement is based on data from SuperKEKB electron-positron collisions at the Υ(4S)\Upsilon(4S) resonance collected with the Belle II detector and corresponding to an integrated luminosity of 362 fb1{362~\text{fb}^{-1}}. The event yields are extracted from fits to the distributions of the difference between expected and observed BB meson energy to separate signal and background, and are efficiency-corrected as a function of the invariant mass of the KKS0K^-K_S^0 system. We find the branching fractions to be: B(BD0KKS0)=(1.89±0.16±0.10)×104, \text{B}(B^-\to D^0K^-K_S^0)=(1.89\pm 0.16\pm 0.10)\times 10^{-4}, B(B0D+KKS0)=(0.85±0.11±0.05)×104, \text{B}(\overline B{}^0\to D^+K^-K_S^0)=(0.85\pm 0.11\pm 0.05)\times 10^{-4}, B(BD0KKS0)=(1.57±0.27±0.12)×104, \text{B}(B^-\to D^{*0}K^-K_S^0)=(1.57\pm 0.27\pm 0.12)\times 10^{-4}, B(B0D+KKS0)=(0.96±0.18±0.06)×104, \text{B}(\overline B{}^0\to D^{*+}K^-K_S^0)=(0.96\pm 0.18\pm 0.06)\times 10^{-4}, where the first uncertainty is statistical and the second systematic. These results include the first observation of B0D+KKS0\overline B{}^0\to D^+K^-K_S^0, BD0KKS0B^-\to D^{*0}K^-K_S^0, and B0D+KKS0\overline B{}^0\to D^{*+}K^-K_S^0 decays and a significant improvement in the precision of B(BD0KKS0)\text{B}(B^-\to D^0K^-K_S^0) compared to previous measurements

    Measurements of the branching fractions for BKγB \to K^{*}\gamma decays at Belle II

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    This paper reports a study of BKγB \to K^{*}\gamma decays using 62.8±0.662.8\pm 0.6 fb1^{-1} of data collected during 2019--2020 by the Belle II experiment at the SuperKEKB e+ee^{+}e^{-} asymmetric-energy collider, corresponding to (68.2±0.8)×106(68.2 \pm 0.8) \times 10^6 BBB\overline{B} events. We find 454±28454 \pm 28, 50±1050 \pm 10, 169±18169 \pm 18, and 160±17160 \pm 17 signal events in the decay modes B0K0[K+π]γB^{0} \to K^{*0}[K^{+}\pi^{-}]\gamma, B0K0[KS0π0]γB^{0} \to K^{*0}[K^0_{\rm S}\pi^{0}]\gamma, B+K+[K+π0]γB^{+} \to K^{*+}[K^{+}\pi^{0}]\gamma, and B+K+[K+π0]γB^{+} \to K^{*+}[K^{+}\pi^{0}]\gamma, respectively. The uncertainties quoted for the signal yield are statistical only. We report the branching fractions of these decays: B[B0K0[K+π]γ]=(4.5±0.3±0.2)×105,\mathcal{B} [B^{0} \to K^{*0}[K^{+}\pi^{-}]\gamma] = (4.5 \pm 0.3 \pm 0.2) \times 10^{-5}, B[B0K0[KS0π0]γ]=(4.4±0.9±0.6)×105,\mathcal{B} [B^{0} \to K^{*0}[K^0_{\rm S}\pi^{0}]\gamma] = (4.4 \pm 0.9 \pm 0.6) \times 10^{-5}, B[B+K+[K+π0]γ]=(5.0±0.5±0.4)×105, and\mathcal{B} [B^{+} \to K^{*+}[K^{+}\pi^{0}]\gamma] = (5.0 \pm 0.5 \pm 0.4)\times 10^{-5},\text{ and} B[B+K+[KS0π+]γ]=(5.4±0.6±0.4)×105,\mathcal{B} [B^{+} \to K^{*+}[K^0_{\rm S}\pi^{+}]\gamma] = (5.4 \pm 0.6 \pm 0.4) \times 10^{-5}, where the first uncertainty is statistical, and the second is systematic. The results are consistent with world-average values

    Angular analysis of B+ρ+ρ0B^+ \to \rho^+\rho^0 decays reconstructed in 2019, 2020, and 2021 Belle II data

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    We report on a Belle II measurement of the branching fraction (B\mathcal{B}), longitudinal polarization fraction (fLf_L), and CP asymmetry (ACP\mathcal{A}_{CP}) of B+ρ+ρ0B^+\to \rho^+\rho^0 decays. We reconstruct B+ρ+(π+π0(γγ))ρ0(π+π)B^+\to \rho^+(\to \pi^+\pi^0(\to \gamma\gamma))\rho^0(\to \pi^+\pi^-) decays in a sample of SuperKEKB electron-positron collisions collected by the Belle II experiment in 2019, 2020, and 2021 at the Υ\Upsilon(4S) resonance and corresponding to 190 fb1^{-1} of integrated luminosity. We fit the distributions of the difference between expected and observed BB candidate energy, continuum-suppression discriminant, dipion masses, and decay angles of the selected samples, to determine a signal yield of 345±31345 \pm 31 events. The signal yields are corrected for efficiencies determined from simulation and control data samples to obtain $\mathcal{B}(B^+ \to \rho^+\rho^0) = [23.2^{+\ 2.2}_{-\ 2.1} (\rm stat) \pm 2.7 (\rm syst)]\times 10^{-6},, f_L = 0.943 ^{+\ 0.035}_{-\ 0.033} (\rm stat)\pm 0.027(\rm syst),and, and \mathcal{A}_{CP}=-0.069 \pm 0.068(\rm stat) \pm 0.060 (\rm syst).Theresultsagreewithpreviousmeasurements.Thisisthefirstmeasurementof. The results agree with previous measurements. This is the first measurement of \mathcal{A}_{CP}in in B^+\to \rho^+\rho^0$ decays reported by Belle II

    Measurement of the branching fractions and CPCP asymmetries of B+π+π0B^+ \rightarrow \pi^+ \pi^0 and B+K+π0B^+ \rightarrow K^+ \pi^0 decays in 2019-2021 Belle II data

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    We determine the branching fractions B{\mathcal{B}} and CPCP asymmetries ACP{\mathcal{A}_{{\it CP}}} of the decays B+π+π0B^+ \rightarrow \pi^+ \pi^0 and B+K+π0B^+ \rightarrow K^+ \pi^0. The results are based on a data set containing 198 million bottom-antibottom meson pairs corresponding to an integrated luminosity of 190  fb1190\;\text{fb}^{-1} recorded by the Belle II detector in energy-asymmetric electron-positron collisions at the Υ(4S)\Upsilon (4S) resonance. We measure B(B+π+π0)=(6.12±0.53±0.53)×106{\mathcal{B}(B^+ \rightarrow \pi^+ \pi^0) = (6.12 \pm 0.53 \pm 0.53)\times 10^{-6}}, B(B+K+π0)=(14.30±0.69±0.79)×106{\mathcal{B}(B^+ \rightarrow K^+ \pi^0) = (14.30 \pm 0.69 \pm 0.79)\times 10^{-6}}, ACP(B+π+π0)=0.085±0.085±0.019{\mathcal{A}_{{\it CP}}(B^+ \rightarrow \pi^+ \pi^0) = -0.085 \pm 0.085 \pm 0.019}, and ACP(B+K+π0)=0.014±0.047±0.010{\mathcal{A}_{{\it CP}}(B^+ \rightarrow K^+ \pi^0) = 0.014 \pm 0.047 \pm 0.010}, where the first uncertainties are statistical and the second are systematic. These results improve a previous Belle II measurement and agree with the world averages

    Determination of Vub|V_{ub}| from untagged B0π+νB^0\to\pi^- \ell^+ \nu_{\ell} decays using 2019-2021 Belle II data

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    We present an analysis of the charmless semileptonic decay B0π+νB^0\to\pi^- \ell^+ \nu_{\ell}, where =e,μ\ell = e, \mu, from 198.0 million pairs of BBˉB\bar{B} mesons recorded by the Belle II detector at the SuperKEKB electron-positron collider. The decay is reconstructed without identifying the partner BB meson. The partial branching fractions are measured independently for B0πe+νeB^0\to\pi^- e^+ \nu_{e} and B0πμ+νμB^0\to\pi^- \mu^+ \nu_{\mu} as functions of q2q^{2} (momentum transfer squared), using 3896 B0πe+νeB^0\to\pi^- e^+ \nu_{e} and 5466 B0πμ+νμB^0\to\pi^- \mu^+ \nu_{\mu} decays. The total branching fraction is found to be (1.426±0.056±0.125)×104(1.426 \pm 0.056 \pm 0.125) \times 10^{-4} for B0π+νB^0\to\pi^- \ell^+ \nu_{\ell} decays, where the uncertainties are statistical and systematic, respectively. By fitting the measured partial branching fractions as functions of q2q^{2}, together with constraints on the nonperturbative hadronic contribution from lattice QCD calculations, the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element VubV_{ub}, (3.55±0.12±0.13±0.17)×103(3.55 \pm 0.12 \pm 0.13 \pm 0.17) \times 10^{-3}, is extracted. Here, the first uncertainty is statistical, the second is systematic and the third is theoretical
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