The Metabolic Factor Kynurenic Acid of Kynurenine Pathway Predicts Major Depressive Disorder

Background: Metabolic factors in the kynurenine pathway (KP) have been widely accepted as being a major mechanism in Major Depressive Disorder (MDD). However, the effects of these metabolites on the degree and pattern of MDD are still poorly understood, partly due to the elusiveness of the level of metabolites when diagnosing depression. This study aimed to explore a novel diagnostic method analyzing peripheral blood with mass spectrometry to assess metabolites from KP in patients with MDD and Bipolar Depression (BD).Methods: Thirty-three patients with MDD, 20 patients with BD, and 23 healthy control participants were enrolled Metabolic factors of KP from plasma including tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QUIN) were analyzed by UPLC-3Q-MS, and levels compared across three groups. Correlation between HAMD scores and metabolite levels conducted. Receiver operating characteristic (ROC) curve was used to determine the diagnostic value of metabolic factors in MDD.Results: Levels of KYNA, QUIN, KYNA/QUIN, and KYNA/KYN were statistically different across the three groups (P < 0.05); HAMD scores and TRP, KYN, KYNA/QUIN levels were negatively correlated in the MDD group (r = −0.633, −0.477, −0.418, P < 0.05); Accuracy of KYNA diagnosing MDD was 82.5% with the optimal diagnostic value being 15.48 ng/ml. Diagnostic accuracy was increased to 83.6% when KYNA and QUIN levels were used in combination.Conclusion: This results indicate that metabolic factors of KP play a crucial role in the occurrence and development of MDD, supporting the metabolic imbalance hypothesis of MDD. Furthermore, our study also provides a new diagnostic method to study MDD based on plasma KYNA level, and suggests that KYNA would be a potential biomarker in diagnosing depression patients

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, 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

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

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

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. 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

Investigating Fine Structures of the Earth’s Interior Based on Spectral-element Seismic-wave Simulations

One of the ultimate goals in the studies of seismic waves is to utilize the entire records of seismograms and exploit these waveforms to map the heterogeneity and anisotropy in the Earth's interior. An important technique towards this goal is full waveform inversion (FWI), which often combines accurate numerical solvers of wave equations with gradient-based iterative model updates. Meanwhile, the model resolved by seismic tomography using the relatively low-frequency component of seismograms is only an equivalent smooth one (i.e., homogenized model) of the complex geological structures (i.e., the Earth). In this thesis, we first present the application of homogenization theory to transversely isotropic models and demonstrate the computational efficiency gained from using effective media in forward seismic wave simulations. An efficient wave-equation solver is vital to FWI as forward modeling is repeatedly used to compute accurate synthetics for the updated model to match the observations. Full numerical solvers based on spectral-element method (SEM) are desirable in this task of resolving fine-scale structures, but the associated computational cost can be prohibitive when the simulation frequency becomes high. Hybrid method can be used to reduce the computational cost by restricting the 2D/3D numerical solver to the target region where complex structures reside. We present the framework of an SEM-based two-way hybrid method where the target region can be anywhere inside the Earth. This two-way hybrid method can help map detailed heterogeneities in the lowermost mantle with the unprecedented resolution of FWI. As part of the work in this thesis to investigate fine-scale structures, we have also systematically measured the apparent splitting of vertically and horizontally polarized diffracted S waves along the core-mantle boundary (CMB) based on cross-correlation traveltimes, choosing Aleutian and west Africa as the study regions. Waveform simulations based upon SEM demonstrate that the SHdiff/SVdiff apparent splitting times from isotropic effects are comparable in magnitude to those from actual observations. These apparent splittings should be attributed to the different SHdiff and SVdiff sensitivities even in isotropic Earth models. Therefore, 1D and 3D isotropic effects, rather than intrinsic anisotropy, need to be first incorporated in the interpretation of SHdiff/SVdiff apparent splitting.Ph.D

Investigating Fine Structures of the Earth’s Interior Based on Spectral-element Seismic-wave Simulations

One of the ultimate goals in the studies of seismic waves is to utilize the entire records of seismograms and exploit these waveforms to map the heterogeneity and anisotropy in the Earth's interior. An important technique towards this goal is full waveform inversion (FWI), which often combines accurate numerical solvers of wave equations with gradient-based iterative model updates. Meanwhile, the model resolved by seismic tomography using the relatively low-frequency component of seismograms is only an equivalent smooth one (i.e., homogenized model) of the complex geological structures (i.e., the Earth). In this thesis, we first present the application of homogenization theory to transversely isotropic models and demonstrate the computational efficiency gained from using effective media in forward seismic wave simulations. An efficient wave-equation solver is vital to FWI as forward modeling is repeatedly used to compute accurate synthetics for the updated model to match the observations. Full numerical solvers based on spectral-element method (SEM) are desirable in this task of resolving fine-scale structures, but the associated computational cost can be prohibitive when the simulation frequency becomes high. Hybrid method can be used to reduce the computational cost by restricting the 2D/3D numerical solver to the target region where complex structures reside. We present the framework of an SEM-based two-way hybrid method where the target region can be anywhere inside the Earth. This two-way hybrid method can help map detailed heterogeneities in the lowermost mantle with the unprecedented resolution of FWI. As part of the work in this thesis to investigate fine-scale structures, we have also systematically measured the apparent splitting of vertically and horizontally polarized diffracted S waves along the core-mantle boundary (CMB) based on cross-correlation traveltimes, choosing Aleutian and west Africa as the study regions. Waveform simulations based upon SEM demonstrate that the SHdiff/SVdiff apparent splitting times from isotropic effects are comparable in magnitude to those from actual observations. These apparent splittings should be attributed to the different SHdiff and SVdiff sensitivities even in isotropic Earth models. Therefore, 1D and 3D isotropic effects, rather than intrinsic anisotropy, need to be first incorporated in the interpretation of SHdiff/SVdiff apparent splitting.Ph.D