355 research outputs found

    Discovering Cooperative Relationships of Chromatin Modifications in Human T Cells Based on a Proposed Closeness Measure

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    BACKGROUND: Eukaryotic transcription is accompanied by combinatorial chromatin modifications that serve as functional epigenetic markers. Composition of chromatin modifications specifies histone codes that regulate the associated gene. Discovering novel chromatin regulatory relationships are of general interest. METHODOLOGY/PRINCIPAL FINDINGS: Based on the premise that the interaction of chromatin modifications is hypothesized to influence CpG methylation, we present a closeness measure to characterize the regulatory interactions of epigenomic features. The closeness measure is applied to genome-wide CpG methylation and histone modification datasets in human CD4+T cells to select a subset of potential features. To uncover epigenomic and genomic patterns, CpG loci are clustered into nine modules associated with distinct chromatin and genomic signatures based on terms of biological function. We then performed Bayesian network inference to uncover inherent regulatory relationships from the feature selected closeness measure profile and all nine module-specific profiles respectively. The global and module-specific network exhibits topological proximity and modularity. We found that the regulatory patterns of chromatin modifications differ significantly across modules and that distinct patterns are related to specific transcriptional levels and biological function. DNA methylation and genomic features are found to have little regulatory function. The regulatory relationships were partly validated by literature reviews. We also used partial correlation analysis in other cells to verify novel regulatory relationships. CONCLUSIONS/SIGNIFICANCE: The interactions among chromatin modifications and genomic elements characterized by a closeness measure help elucidate cooperative patterns of chromatin modification in transcriptional regulation and help decipher complex histone codes

    Study of the BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

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    The decay BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} is studied in proton-proton collisions at a center-of-mass energy of s=13\sqrt{s}=13 TeV using data corresponding to an integrated luminosity of 5 fb1\mathrm{fb}^{-1} collected by the LHCb experiment. In the Λc+K\Lambda_{c}^+ K^{-} system, the Ξc(2930)0\Xi_{c}(2930)^{0} state observed at the BaBar and Belle experiments is resolved into two narrower states, Ξc(2923)0\Xi_{c}(2923)^{0} and Ξc(2939)0\Xi_{c}(2939)^{0}, whose masses and widths are measured to be m(Ξc(2923)0)=2924.5±0.4±1.1MeV,m(Ξc(2939)0)=2938.5±0.9±2.3MeV,Γ(Ξc(2923)0)=0004.8±0.9±1.5MeV,Γ(Ξc(2939)0)=0011.0±1.9±7.5MeV, m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV}, where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt Λc+K\Lambda_{c}^{+} K^{-} sample. Evidence of a new Ξc(2880)0\Xi_{c}(2880)^{0} state is found with a local significance of 3.8σ3.8\,\sigma, whose mass and width are measured to be 2881.8±3.1±8.5MeV2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV} and 12.4±5.3±5.8MeV12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}, respectively. In addition, evidence of a new decay mode Ξc(2790)0Λc+K\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-} is found with a significance of 3.7σ3.7\,\sigma. The relative branching fraction of BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} with respect to the BD+DKB^{-} \to D^{+} D^{-} K^{-} decay is measured to be 2.36±0.11±0.22±0.252.36 \pm 0.11 \pm 0.22 \pm 0.25, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

    Measurement of the ratios of branching fractions R(D)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

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    The ratios of branching fractions R(D)B(BˉDτνˉτ)/B(BˉDμνˉμ)\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu}) and R(D0)B(BD0τνˉτ)/B(BD0μνˉμ)\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu}) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb1{ }^{-1} of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τμντνˉμ\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}. The measured values are R(D)=0.281±0.018±0.024\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024 and R(D0)=0.441±0.060±0.066\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ=0.43\rho=-0.43. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

    Tourism Eco-Efficiency Measurement, Characteristics, and Its Influence Factors in China

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    As an emerging field of eco-efficiency, tourism eco-efficiency is becoming an important way to measure the sustainable development of tourism. This study calculated and decomposed tourism CO2 emissions in China, explored its evolution and distribution characteristics by using the ratio method of tourism eco-efficiency, and analyzed the influencing factors by adopting a regression model. The results indicate that: (1) tourism CO2 emissions in China have increased significantly, their largest source is transportation. Its characteristics can be divided into carbon emission intensity factor, income structure factor, consumption level factor, and tourist scale factor through utilizing the Logarithmic Mean Divisia Index (LMDI) method, which also shows that the decisive factor of increased of tourism CO2 emissions has been the tourist scale factor. (2) Tourism eco-efficiency is marked by spectacular but unstable growth, which can be divided into three stages: inefficient stagnation stage, fluctuating growth stage, and efficient development stage. (3) Tourism eco-efficiency in China has shown that the remarkable high–high cluster and low–low cluster, and the 31 provinces, can be divided into four groups, namely: a high-efficiency high-growth group, a high-efficiency low-growth group, a low-efficiency high-growth group, and a low-efficiency low-growth group. (4) The main influencing factors of tourism eco-efficiency are the scale effect, the structural effect, the technical effect, and the environmental regulation. Since these four factors have different impacts on the tourism eco-efficiency of different groups according to panel data regression, more effective policies should be adopted for the improvement of tourism eco-efficiency in China. Finally, the significances and deficiencies of this study are discussed

    Consecutive drilling combined with phaco chop for full thickness segmentation of very hard nucleus in coaxial microincisional cataract surgery

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    Abstract Background The complete disassembly of nuclear is the most challenging step in hard cataract surgery through microincision. The classic phaco chop technique often does not succeed, resulting in incomplete nuclear segmentation. The authors describe a technique to improve the efficacy and safety of the initial chopping. Methods The consecutive drilling combined with phaco chop technique was devised for very hard cataract through a microincision of 1.8–2.2 mm. 3–4 holes are consecutively drilled into the endonucleus with the phaco tip bevel down, at an angle of approximate 60 degrees and depth of approximately two-thirds of the lens thickness. The initial drilling approaches the capsulorhexis edge and the last drilling approaches the lens geometric center. The nucleus is deeply impaled with the last drilling and firmly engaged with high vacuum, and then chopped with chopper centripetally from the lens equator. The chopper and phaco tip are spread apart laterally after they approach at the center of the nucleus, to create a complete fracture across the entire nucleus. This technique has been adopted in 80 eyes of 65 patients with cataract harder than nuclear opalescence 5 on the Lens Opacities Classification System III scale or mature white cataract with a hard nucleus in the past 12 months. Results In all cases, full thickness segmentation of the hard nuclear including the posterior plate was achieved with this consecutive drilling combined with phaco chop technique. Phacoemulsification and intracapsular implantation of intraocular lens was safely performed in each case. No intraoperative complication such as iris injury, anterior capsule tears, zonulysis or posterior capsule rupture with vitreous loss occurred during surgery. No postoperative complication such as fibrin formation, synechias, severe endothelial cell loss, or endophthalmitis was observed in any case at 6 months postoperatively. Conclusions The technique is an efficient, safe, simple, and swift procedure for full-thickness nuclear segmentation, delivering advantage of microincisional phacoemulsifcation for hard cataract with few ocular complications

    Macular perfusion density evaluation in constant and intermittent exotropia by means of optical coherence tomography angiography

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    Abstract Background To quantify and compare retinal microvascular features using optical coherence tomography angiography (OCTA) in constant (XT) and intermittent exotropia (IXT). Methods An observational cross-sectional study was conducted from September 2020 to November 2020 at the Affiliated Eye Hospital of Wenzhou Medical University. OCTA examination was performed to evaluate the macular perfusion density of the deep capillary plexus (DCP), superficial capillary plexus (SCP), and foveal avascular zone (FAZ) parameters in XT and IXT patients, and in age-matched controls. The study parameters were analyzed. Results A total of 76 participants, including 16 (21%) XT patients, 24 (32%) IXT patients, and 36 (47%) controls, were recruited. The exodeviation angle was 39.06 ± 10.38 prism degrees (PD) at near and 43.00 ± 9.74 PD at distance in the XT group, and 27.13 ± 18.28 PD at near and 31.04 ± 18.82 PD at distance in the IXT group. The macular perfusion density of the DCP in 6 × 6-mm scans and the SCP in 3 × 3-mm scans were lower in the deviating eyes than in the fixating eyes of XT patients (p < 0.001, p = 0.032, respectively). The macular perfusion density of the DCP in the deviating eyes of XT and IXT patients was significantly lower than that of the controls. There was no significant difference in the FAZ parameters among the groups. Conclusions In XT patients, OCTA revealed lower macular perfusion density in deviating eyes than in fixating eyes and control eyes. IXT patients showed no difference between the two eyes, but the macular perfusion density of the DCP was lower than that of the controls

    Effects of <i>Clostridium butyricum</i> on Intestinal Microflora and Metabolism of <i>Eriocheir sinensis</i>

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    Clostridium butyricum, a new probiotic in recent years, can produce butyric acid and short-chain fatty acids. It has the characteristics of strong acid and alkali resistance, high temperature resistance, and strong resistance to most antibiotics, and has more advantages than other probiotics. However, the action mechanism of C. butyricum on Eriocheir sinensis is still unclear and needs further study. In this study, when C. butyricum was added to the basic diet, the number of living bacteria was 0, 1 × 106 and 1 × 108 CFU/g, respectively. The E. sinensis were randomly divided into three groups: (blank control group, experimental group 1 (1 × 106 CFU/g) and experimental group 2 (1 × 108 CFU/g)). They were fed an experimental diet for 28 days. The effects of C. butyricum on E. sinensis were studied by detecting the differences in non-specific immune indexes, intestinal microflora, and metabolites between serum and hepatopancreas. The results showed that C. butyricum could improve the antioxidant ability of E. sinensis serum and hepatopancreas, protect intestinal tissues, and promote the absorption of nutrients. At the same time, it can enhance the microbial diversity and richness of the E. sinensis gut flora. LC-MS metabolomics was used to detect the metabolism of intestinal flora. It was found that C. butyricum could up-regulate lysophosphatidylcholine in the intestine. Through the KEGG enrichment pathway, it was found that significantly different metabolites were mainly concentrated in six metabolic pathways. The purine metabolism and alanine, aspartate, and glutamate metabolism pathways showed a downward trend, indicating that the addition of C. butyricum to feed could reduce purine metabolism, promote the water-salt balance of the organism’s cells, and reduce inflammation. In this study, it was found that the addition of certain concentrations of C. butyricum to feed could improve the antioxidant ability of E. sinensis, improve the intestinal flora environment, and promote the growth of beneficial bacteria in the gut. This can promote the body’s metabolism, which is more conducive to its growth

    Implicit trust between the Uyghur and the Han in Xinjiang, China.

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    Trust is a vital lubricant that increases the sense of security in social interactions. In this study, we investigated the intergroup trust between the Uyghur and the Han, the two largest ethnic groups in Xinjiang, China, with a Go/No-Go Association Task. Specifically, we instructed Uyghur and Han participants to respond to ethnic faces (Uyghur vs. Han) and trust/distrust words and measured the strength of the automatic associations between the faces and words for both in-group and out-group pairs. As expected, both ethnic groups showed implicit in-group trust and out-group distrust, but the Han group demonstrated stronger in-group trust and out-group distrust toward the Uyghur than the Uyghur group toward the Han. However, the magnitude of distrust of the Han toward the Uyghur was small to medium as compared with that reported by other intergroup relationship research. In addition, participant geographic location was associated with out-group distrust. These findings offer implications for developing effective strategies to encourage trust between conflicting groups

    Research on an On-Chip MEMS Based Safety and Arming Device with a Mechanical Encryption System

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    The design and characterization of microelectromechanical systems (MEMS) based on-chip SAD (Safety and Arming Device) are proposed. An encryption system has been integrated into the device to enhance its reliability during the electromagnetic interference. The conversion between safe status and arm status is reversible due to the bidirectional actuation design of the slider and pawl on the SOI (Silicon on Insulator) chip, being driven by the chevron electrothermal actuators. The width of each tooth on the slider, which contains coding information, is different from that of its adjacent neighbor. Additionally, the different teeth width, respectively 32 &mu;m, 82 &mu;m, requiring different decoding displacement of 100 &mu;m and 150 &mu;m, corresponds to the different decoding voltage of 13.5 V and 14.8 V. The travel range of interrupter in the SAD will only be limited by the chip dimension and be able to cover the motion of &plusmn;1 mm in the present research, due to the capability of motion retention. Finally, the SAD is integrated with a copper azide exploding chip to measure the average velocity of the titanium flyer for the application feasibility validation
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