Search

The semitauonic $$ {B}_c^{-}\to J/\psi {\tau}^{-}{\overline{\nu}}_{\tau } $$ B c − → J / ψ τ − ν ¯ τ decay provides an ideal and clean mode to scrutinize possible new physics effects in $$ b\to c{\tau}^{-}{\overline{\nu}}_{\tau } $$ b → c τ − ν ¯ τ transitions as indicated by the current data on R(D(*)) anomalies. In this work, we use the spin density matrix method to obtain the maximum information on the underlying physics of $$ {B}_c^{-}\to J/\psi {\tau}^{-}{\overline{\nu}}_{\tau } $$ B c − → J / ψ τ − ν ¯ τ decay with both polarized τ lepton and J/ψ meson. Their subsequent decays, with J/ψ → μ+μ− as well as τ− → π−ντ, τ− → ρ−ντ and $$ {\tau}^{-}\to {\ell}^{-}{\overline{\nu}}_{\ell }{\nu}_{\tau } $$ τ − → ℓ − ν ¯ ℓ ν τ , are exploited to extract the energy and angular distributions of the charged final-state particles in the processes. Starting with the most general effective Hamiltonian relevant for the $$ b\to c{\tau}^{-}{\overline{\nu}}_{\tau } $$ b → c τ − ν ¯ τ transitions, including all possible Lorentz structures of the dimension-six operators with both left- and right-handed neutrinos, we first derive the five-fold differential decay rate in terms of the visible final-state kinematics. From this distribution, we then construct in total 34 normalized observables, among which nine refer to the CP-violating triple product asymmetries that vanish within the Standard Model. We also construct five new observables based on the combinations of these normalized observables that can only be attributed to the right-handed neutrinos. On the other hand, considering the low statistics of the fully differential distribution, we introduce some integrated observables with only one kinematic variable left, which are more promising to be measured due to the largely increased statistics. The sensitivities of all these observables to the different new physics scenarios are investigated in detail. Finally, assuming an ideal circumstance, we give an estimate of the statistical uncertainties of the nine CP-conserving observables at LHCb and found that τ− → π−ντ has the highest analyzing power among the three τ decay channels.

There is growing evidence that air pollution plays a role in TB, but few studies have comprehensively included the six common air pollutants. Our objectives were to investigate the association between short-term exposure to six common air pollutants and the risk of tuberculosis outpatient visits in Fuyang, China, during the period 2015-2020. We combined the two models to explore the effects of exposure to six air pollutants on the risk of tuberculosis outpatient visits, including Poisson generalized linear regression model and distributed lag non-linear model (DLNM). We performed stratified analyses for season, gender and age. We used the lag-specific relative risks and cumulative relative risk obtained by increasing pollutant concentration by per 10 units to evaluate the connection between six air pollutants and TB, PM2.5 (RR=1.0018, 95%CI: 1.0004-1.0032, delay of 12 days) and (RR=1.0169,95%CI: 1.0007-1.0333, lag 0-16 days), SO2 were 0.9549 (95%CI: 0.9389-0.9712, lag 0 days) and 0.8212 (95%CI: 0.7351-0.9173, 0-20 days lag). Stratified analyses showed that seasonal differences had a greater impact on TB, and male more likely to develop TB than female, older people more likely to develop TB than younger people. Exposure to O3, CO, PM10, PM2.5, and NO2 increases the risk of TB outpatient visits, except SO2 reduces the risk. Male and elderly people should be protected. We need to pay more attention to the impact of seasonal effects on TB.

We update the Standard Model (SM) predictions for the branching ratios of the rare top-quark decays $$t \rightarrow cg(g)$$ t → c g ( g ) , and evaluate the maximum rates that can be reached in the aligned as well as in the four conventional two-Higgs-doublet models (2HDMs) with $$\mathcal {Z}_2$$ Z 2 symmetries. Taking into account the relevant constraints on the model parameters resulting from a global fit obtained at the $$95.5\%$$ 95.5 % confidence level, we find that the branching ratios of $$t \rightarrow cg$$ t → c g and $$t \rightarrow cgg$$ t → c g g decays can reach up to $$3.36\times 10^{-9}$$ 3.36 × 10 - 9 and $$2.95\times 10^{-9}$$ 2.95 × 10 - 9 respectively, being therefore of the same order, in the aligned 2HDM (A2HDM). This is obviously different from the SM case, where the predicted branching ratio of the three-body decay $$t \rightarrow cgg$$ t → c g g is about two orders of magnitude larger than that of the two-body decay $$t \rightarrow cg$$ t → c g . On the other hand, compared with the SM predictions, no significant enhancements are observed in the four conventional 2HDMs with $$\mathcal {Z}_2$$ Z 2 symmetries for the branching ratios of these two decays. Nevertheless, the predicted branching ratios of $$t \rightarrow cg$$ t → c g and $$t \rightarrow cgg$$ t → c g g decays in the A2HDM are still out of the expected sensitivities of the future high-luminosity Large Hadron Collider and the Future Circular Collider in hadron-hadron mode.

A novel virulent phage, vB_KpnP_IME337, isolated from a hospital sewage in Beijing, China, that infects carbapenem-resistant Klebsiella pneumoniae KN2 capsular type was identified and characterized. Next-generation sequencing and genome analysis revealed that vB_KpnP_IME337 had a linear double-stranded genome with a length of 44,266 base pairs and G+C content of 53.7%. Fifty-two putative open reading frames were identified, and no transfer RNA-encoding genes were detected. BLASTn analysis revealed that phage vB_KpnP_IME337 had the highest sequence similarity with Klebsiella phage phiBO1E, with genome coverage of 79%. Based on morphology, phage vB_KpnP_IME337 was determined to belong to the family Podoviridae of the order Caudovirales. It was shown that phage vB_KpnP_IME337 had an infection duration of ~ 90 min and 10 min latent period, and a highly specific to host strain. In conclusion, phage vB_KpnP_IME337 may be a promising alternative candidate to antibiotic treatment for controlling diseases caused by drug-resistant K. pneumoniae.

Epigallocatechin gallate (EGCG) has the effect to protect skin from ultraviolet B (UVB) induced damages, but it is unstable under ambient conditions, being susceptible to become brown in color. Gallocatechin gallate (GCG), an epimer counterpart of EGCG, is more stable chemically than EGCG. The potential effects of GCG against UVB-induced skin damages has not been available. The objective of this study was to investigate the protective effects of GCG against UVB-induced skin photodamages. GCG was topically applied on the skin of hairless mice at three dosage levels (LL, 12.5 mg/mL; ML 25 mg/mL; HL, 50 mg/mL), with EGCG and a commercially available baby sunscreen lotion SPF50 PA+++ as control. The mice were then irradiated by UVB (fluence rate 1.7 µmol/m2 s) for 45 min. The treatments were carried out once a day for 6 consecutive days. Skin measurements and histological studies were performed at the end of experiment. The results show that GCG treatments at ML and HL levels inhibited the increase in levels of skin oil and pigmentation induced by UVB irradiation, and improved the skin elasticity and collagen fibers. GCG at ML and HL levels inhibited the formation of melanosomes and aberrations in mitochondria of UVB-irradiated skin in hairless mice. It is concluded that GCG protected skin from UVB-induced photodamages by improving skin elasticity and collagen fibers, and inhibiting aberrations in mitochondria and formation of melanosomes.

Background Persons living with dementia have various health and social care needs and expectations, some which are not fully met by health providers, including primary care clinicians. The Quebec Alzheimer plan, implemented in 2014, aimed to cover these needs, but there is no research on the effect this plan had on the needs and expectations of persons living with dementia. The objective of this study is to identify persons living with dementia and caregivers’ met and unmet needs and to describe their experience. Methods This is a sequential mixed methods explanatory design: Phase 1: cross-sectional study to describe the met and unmet health and social care needs of community-dwelling persons living with dementia using Camberwell Assessment of Need of the Elderly and Carers’ Assessment for Dementia tools. Phase 2: qualitative descriptive study to explore and understand the experiences of persons living with dementia and caregivers with the use of social and healthcare services, using semi-structured interviews. Data from phase 1 was analyzed with descriptive statistics, and from phase 2, with inductive thematic analysis. Results from phases 1 and 2 were compared, contrasted and interpreted together. Results The mean total number of needs reported by the patients was 5.03 (4.48 and 0.55 met and unmet needs, respectively). Caregivers had 0.52 met needs (3.16 unmet needs). The main needs for both were memory, physical health, eyesight/hearing/communication, medication, looking after home, money/budgeting. Three categories were mentioned by the participants: Persons living with dementia and caregiver’s attitude towards memory decline, their perception of community health services and of the family medicine practice. Conclusions Our study confirms the findings of other studies on the most common unmet needs of the patients and caregivers that are met partially or not at all. In addition, the participants were satisfied with access to care, and medical services in primary practices, being confident in their family. Our results indicate persons living with dementia and their caregivers need a contact person, a clear explanation of their dementia diagnosis, a care plan, written information on available services, and support for the caregivers.

In $$ {B}_c^{-} $$ B c − → J/ψ(→ μ+μ−)τ−$$ {\overline{\nu}}_{\tau } $$ ν ¯ τ decay, the three-momentum $$ {\boldsymbol{p}}_{\tau^{-}} $$ p τ − cannot be determined accurately due to the decay products of τ− inevitably include an undetected ντ. As a consequence, the angular distribution of this decay cannot be measured. In this work, we construct a measurable angular distribution by considering the subsequent decay τ− → π−ντ. The full cascade decay is $$ {B}_c^{-} $$ B c − → J/ψ(→ μ+μ−)τ−(→ π−ντ)$$ {\overline{\nu}}_{\tau } $$ ν ¯ τ , in which the three-momenta $$ {\boldsymbol{p}}_{\mu^{+}},{\boldsymbol{p}}_{\mu^{-}} $$ p μ + , p μ − , and $$ {\boldsymbol{p}}_{\pi^{-}} $$ p π − can be measured. The five-fold differential angular distribution containing all Lorentz structures of the new physics (NP) effective operators can be written in terms of twelve angular observables ℐi(q2, Eπ). Integrating over the energy of pion Eπ, we construct twelve normalized angular observables $$ {\hat{\mathrm{\mathcal{I}}}}_i $$ ℐ ̂ i (q2) and two lepton-flavor-universality ratios $$ R\left({P}_{L,T}^{J/\psi}\right) $$ R P L , T J / ψ (q2). Based on the Bc → J/ψ form factors calculated by the latest lattice QCD and sum rule, we predict the q2 distribution of all $$ {\hat{\mathrm{\mathcal{I}}}}_i $$ ℐ ̂ i and $$ R\left({P}_{L,T}^{J/\psi}\right) $$ R P L , T J / ψ both within the Standard Model and in eight NP benchmark points. We find that the benchmark BP2 (corresponding to the hypothesis of tensor operator) has the greatest effect on all ℐi and $$ R\left({P}_{L,T}^{J/\psi}\right) $$ R P L , T J / ψ , except $$ {\hat{\mathrm{\mathcal{I}}}}_5 $$ ℐ ̂ 5 . The ratios $$ R\left({P}_{L,T}^{J/\psi}\right) $$ R P L , T J / ψ are more sensitive to the NP with pseudo-scalar operators than the ℐi. Finally, we discuss the symmetries in the angular observables and present a model-independent method to determine the existence of tensor operators.

In $$ {\Lambda}_b^0\to {\Lambda}_c^{+}\left(\to {\Lambda}^0{\pi}^{+}\right){\tau}^{-}{\overline{v}}_{\tau } $$ Λ b 0 → Λ c + → Λ 0 π + τ − v ¯ τ decay, the solid angle of the final-state particle τ− cannot be determined precisely since the decay products of the τ− include an undetected ντ. Therefore, the angular distribution of this decay cannot be measured. In this work, we construct a measurable angular distribution by considering the subsequent decay τ−→ π−ντ. The full cascade decay is $$ {\Lambda}_b^0\to {\Lambda}_c^{+}\left(\to {\Lambda}^0{\pi}^{+}\right){\tau}^{-}\left(\to {\pi}^{-}{v}_{\tau}\right){\overline{v}}_{\tau } $$ Λ b 0 → Λ c + → Λ 0 π + τ − → π − v τ v ¯ τ . The three-momenta of the final-state particles Λ0, π+, and π− can be measured. Considering all Lorentz structures of the new physics (NP) effective operators and an unpolarized initial Λb state, the five-fold differential angular distribution can be expressed in terms of ten angular observables $$ {\mathcal{K}}_i\left({q}^2,{E}_{\pi}\right) $$ K i q 2 E π . By integrating over some of the five kinematic parameters, we define a number of observables, such as the Λc spin polarization $$ {P}_{\Lambda_c}\left({q}^2\right) $$ P Λ c q 2 and the forward-backward asymmetry of π− meson AFB(q2), both of which can be represented by the angular observables $$ {\hat{\mathcal{K}}}_i\left({q}^2\right) $$ K ̂ i q 2 . We provide numerical results for the entire set of the angular observables $$ {\hat{\mathcal{K}}}_i\left({q}^2\right) $$ K ̂ i q 2 and $$ {\hat{\mathcal{K}}}_i $$ K ̂ i both within the Standard Model and in some NP scenarios, which are a variety of best-fit solutions in seven different NP hypotheses. We find that the NP which can resolve the anomalies in $$ \overline{B}\to {D}^{\left(\ast \right)}{\tau}^{-}{\overline{v}}_{\tau } $$ B ¯ → D ∗ τ − v ¯ τ decays has obvious effects on the angular observables $$ {\hat{\mathcal{K}}}_i\left({q}^2\right) $$ K ̂ i q 2 , except $$ {\hat{\mathcal{K}}}_{1 ss}\left({q}^2\right) $$ K ̂ 1 ss q 2 and $$ {\hat{\mathcal{K}}}_{1 cc}\left({q}^2\right) $$ K ̂ 1 cc q 2 .

The ongoing outbreak of viral pneumonia in China and across the world is associated with a new coronavirus, SARS-CoV-21. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection2. Although bats are probable reservoir hosts for SARS-CoV-2, the identity of any intermediate host that may have facilitated transfer to humans is unknown. Here we report the identification of SARS-CoV-2-related coronaviruses in Malayan pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin-associated coronaviruses that belong to two sub-lineages of SARS-CoV-2-related coronaviruses, including one that exhibits strong similarity in the receptor-binding domain to SARS-CoV-2. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 suggests that pangolins should be considered as possible hosts in the emergence of new coronaviruses and should be removed from wet markets to prevent zoonotic transmission.

Elucidation of the molecular mechanism related to the dedifferentiation and redifferentiation during tissue culture will be useful for optimizing regeneration system of tea plant. In this study, an integrated sRNAome and transcriptome analyses were carried out during phase changes of the stem explant culture. Among 198 miRNAs and 8001 predicted target genes, 178 differentially expressed miRNAs and 4264 potential targets were screened out from explants, primary calli, as well as regenerated roots and shoots. According to KEGG analysis of the potential targets, pathway of “aminoacyl-tRNA biosynthesis”, “proteasome” and “glutathione metabolism” was of great significance during the dedifferentiation, and pathway of “porphyrin and chlorophyll metabolism”, “mRNA surveillance pathway”, “nucleotide excision repair” was indispensable for redifferentiation of the calli. Expression pattern of 12 miRNAs, including csn-micR390e, csn-miR156b-5p, csn-miR157d-5p, csn-miR156, csn-miR166a-3p, csn-miR166e, csn-miR167d, csn-miR393c-3p, csn-miR394, csn-miR396a-3p, csn-miR396 and csn-miR396e-3p, was validated by qRT-PCR among 57 differentially expressed phase-specific miRNAs. Validation also confirmed that regulatory module of csn-miR167d/ERF3, csn-miR156/SPB1, csn-miR166a-3p/ATHB15, csn-miR396/AIP15A, csn-miR157d-5p/GST and csn-miR393c-3p/ATG18b might play important roles in regulating the phase changes during tissue culture of stem explants.

The purposes of this study were to investigate the activation and transport of atrazine in the presence of dissolved organic matter (DOM) and the surfactant (Triton X-100) and to understand interactions between DOM, Triton X-100, and atrazine. Uncontaminated soils collected from Nanjing, China, along with DOM extracted from rice straw and Triton X-100 (TX-100), were used in the study. The sorption and desorption experiments were carried out using the standard batch equilibration analysis. Soil column leaching was conducted with soil samples packed into PVC columns. Soil thin-layer chromatography was performed using soil and water mixture spread on a 0.5–0.7-mm-thick layer over 20 × 10-cm glass plates. Atrazine accumulation in maize was determined by planting maize in plastic pots (1 L) containing 1 kg soil mixed with 1.0 mg kg−1 atrazine. Soils were watered with different solutions, with the relative water content of 60%. Using batch experiment and soil thin-layer chromatography, application of DOM and surfactant reduced sorption and increased desorption of atrazine in soil. In column experiment, DOM and surfactant significantly promoted the mobility of atrazine in soil and the total concentration of atrazine in leachate of the soil column. Accumulation of atrazine in both maize roots and shoots increased with the elevated concentration of surfactant, whereas the content of atrazine declined with the increase of the DOM concentration. Dissolved organic matter and TX-100 affected the partitioning and transport of atrazine in soil–water and soil–plant ecosystems.

The influence of different contents of Cr, Mo, and rare earth element (RE) additives on the thermal conductivity of austenitic medium manganese steel was studied and discussed. The results show that the addition of Cr in medium manganese steel can improved the ordering of C–Mn atomic clusters, so as to improve the steel’s thermal conductivity. However, Cr will lead to precipitation of a great deal of carbides in medium manganese steel when its content is greater than 4wt%. These carbides would aggregate around the grain boundary, and as a result, the thermal conductivity is decreased. By the addition of Mo whose content is about 2wt%, spherical carbides will be formed, thus improving the thermal conductivity of the medium manganese steel. The interaction between rare earth elements and alloying elements will raise both the thermal conductivity and the wear-resisting property of medium manganese steel.